PLEASE HELP WILL MARK BRAINLIEST!

Answer:

Step-by-step explanation:

The decay rate of strontium-90 is -.0244 as given.

For b., we have to use the formula to find out how much is left after 30 years. This will be important for part d.

[tex]A(t)=400e^{-.0244(30)}[/tex] which simplifies a bit to

A(t) = 400(.4809461353) so

A(t) = 192.4 g

For c., we have to find out how long it takes for the initial amount of 400 g to decay to 100:

[tex]100=400e^{-.0244t}[/tex]. Begin by dividing both sides by 400:

[tex].25=e^{-.0244t[/tex] and then take the natural log of both sides:

[tex]ln(.25)=lne^{-.0244t[/tex] . The natural log and the e cancel each other out since they are inverses of one another, leaving us with:

ln(.25) = -.0244t and divide by -.0244:

61.8 years = t

For d., we figured in b that after 30 years, 192.4 g of the element was left, so we can use that to solve for the half-life in a different formula:

[tex]A(t)=A_0(.5)^{\frac{t}{H}[/tex] and we are solving for H. Filling in:

[tex]192.4=400(.5)^{\frac{30}{H}[/tex] and begin by dividing both sides by 400:

[tex].481=(.5)^{\frac{30}{H}[/tex] and take the natural log of both sides, which allows us to pull the exponent out front. I'm going to include that step in with this one:

ln(.481) = [tex]\frac{30}{H}[/tex] ln(.5) and then divide both sides by ln(.5):

[tex]\frac{ln(.481)}{ln(.5)}=\frac{30}{H}[/tex] and cross multiply and isolate the H to get:

[tex]H=\frac{30ln(.5)}{ln(.481)}[/tex] and

H = 28.4 years

Answer:

b = [tex]\frac{1+2a}{3a-1}[/tex]

Step-by-step explanation:

Given

a = [tex]\frac{b+1}{3b-2}[/tex] ( multiply both sides by 3b - 2 )

a(3b - 2) = b + 1 ← distribute left side

3ab - 2a = b + 1 ( subtract b from both sides )

3ab - b - 2a = 1 ( add 2a to both sides )

3ab - b = 1 + 2a ← factor out b from each term on the left side

b(3a - 1) = 1 + 2a ( divide both sides by 3a - 1 )

b = [tex]\frac{1+2a}{3a-1}[/tex]

Answer:

[tex]→a = \frac{(b + 1)}{(3b - 2)} \\ a(3b - 2) = (b + 1) \\ 3ab - 2a = b + 1 \\ 3ab - b = 2a + 1 \\ b(3a - 1) =( 2a + 1) \\ \boxed{b = \frac{(2a + 1)}{(3a - 1)} }✓[/tex]

Answer:

81/25

Step-by-step explanation:

change 3.24 into faction

324 over 100 because there are two decimal points .

simplfy into the smallest fraction

the answer is 81 over 25

Step-by-step explanation:

here is your answer it may help you

There are 700 don't like to admit in both faculties.

The process of combining two or more numbers is called the Addition. The 4 main properties of addition are commutative, associative, distributive, and additive identity.

Given that;

In a survey, survey of 1200 students who have passed SEE 150 like to admit in science Faculty 600 in humanity first and 240 like to admit either of faculties and the rest were found not to be admitted in both faculties​

Hence, not to be admit in any faculty =   N

Science +  Humanity -  Either   + None  = 200

=> 150 + 600 - 240 + N = 1200

=> 750 - 240 + N = 1200

=> N = 700

Hence, 700 don't like to admit in both faculties.

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Answer:

answer is 12

Step-by-step explanation:

gcf = 3

lcm = 180

let 45 be y

let unknown be X

to get x

X=( lcm * gcf) / y

X=(180*3)/45

X=(540)/45

X=12

the other number is 12

Answer:

1605

Step-by-step explanation:

Answer:

16 baskets

Step-by-step explanation:

Create a proportion where x is the number of baskets that Scott made:

[tex]\frac{14}{21}[/tex] = [tex]\frac{x}{24}[/tex]

Cross multiply and solve for x:

21x = 336

x = 16

So, Scott made 16 baskets.

Answer:

3/5

Step-by-step explanation:

um 3/5+2/5 = 1

Answer:

A)   ± 54 cm^3 ( maximum possible error in volume )

B) i) 58.625 cm^3  ii) 49.625 cm^3

Step-by-step explanation:

A) using differential

edge of cube = 6 cm ,  maximum possible error = 0.5 cm

∴ side of cube ( x )= ± 0.5 cm

V = volume of cube

dv /dx = d(x)^3 / dx

∴ dv  = 3x^2 dx ---- ( 1 )

input values into 1

dv = 3(6)^2 * ( ± 0.5 )

    = ± 54 cm^3 ( maximum possible error in volume )

B) Using calculator

actual error in measuring volume when

i) radius = 6.5 cm instead of  6 cm

V1= ( 6.5)^3 = 274.625 ,  V = ( 6)^3 = 216

actual error = 274.625 - 216 = 58.625 cm^3

ii) radius = 5.5cm instead of 6cm

actual error = 49.625 cm^3

Answer:

-4y^2 + 4x +4

Step-by-step explanation:

add -y^2 and -3y^2 = -4y^2

add 2x + 2x = 4x

add 3+1 = 4

and then rearrange

5.4 km

0.8×6

0.8×0.75

4.8+0.6 =5.4

4/5 of a kilometer = 800m

6 1/8 minutes = 49/8 min

Now

800×49/8

= 100×49

= 4900m

= 4.9km

Must click thanks and mark brainliest

Answer:

Ex. 45° & 89°

Step-by-step explanation:

Acute angles are angles less than 90°. Therefore, any angle less than 90° will do.

Answer:

acute angles are angles which are less than 90° .

For example . A angle with 50°.

more examples of acute angels are : 78° , 60° , 45° , 30 ° .

hope this helps you

mrk me braniliest

The period of days (value of x) for which Faizal promised to pay the bank RM 2,000 after getting 7% discounted present value of RM 1,930 is 180 days.

The value of x is the period of days (number of days) that the loan from the bank will last before Faizal, who received RM 1,930 discounted at 7%, would repay the bank the principal and interest of RM 2,000.

This implies that Faizal is paying an interest of RM 70 (RM 2,000 - RM 1,930), since he borrowed RM 1,930 and will repay RM 2,000.

Data and Calculations:

Present value of loan received = RM 1,930

Discount rate per year = 7%

Future value of the loan to be repaid to the bank = RM 2,000

Interest expense for one year based on 7% = RM 140 (RM 2,000 x 7%)

Interest expense for 180 days or 6 months = RM 70 (RM 2,000 - RM 1,930) or (RM 2,000 x 7%) x 180/360

Interest expense that equals RM 70 will be half of a year or 180 days (RM 140 * 180/360)

Thus, the period of days (x) that will lapse for Faizal to repay the bank is 180 days or half of a year (6 months).

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Answer:

62.5 square miles

Step-by-step explanation:

if the scale is 1 in. = 5 mi, then 1 square in. = 25 square miles

so if 1 in^2 = 25 mi^2

then you make a proportion

25/1 = x/2.5

(the square inches on the bottom and the square miles on top)

solving for x gives you

x=62.5 square miles

Answer:

C. 0

Step-by-step explanation:

Since we are finding f(-4), we use the first function since -4 is less than -2.

f(-4) = (-4) + 4 = 0

Therefore, the answer is C.

Answer:

H0 : μYellow = μGreen

H1 : μYellow < μGreen

Step-by-step explanation:

Let :

Yellow paper = μYellow

Green paper = μGreen

To test the hypothesis :

The null hypothesis is will state that there is no difference in mean of anxiety scores obtained for test taken of yellow and green papers

H0 : μYellow = μGreen.

The alternative hypothesis is the opposite of the null and it is to the left, where we want to test if the anxiety score is lower when take on a yellow paper

H1 : μYellow < μGreen

Answer:

2x³ - x² - 10x + 5

Step-by-step explanation:

Use FOIL method.

(x² - 5) (2x - 1) = x²*2x +(x²)*(-1) + (-5)*(2x) + (-5)*(-1)

                       = 2x³ - x² - 10x + 5

Answer:

π×64×4=804.25

Step-by-step explanation:

Formula of cylinder is π×square of radius×height

Answer:

803.8

Step-by-step explanation:

it's 3.14×8×8×4 which would give you 803.84 and then you round which would give you 803.8

Answer:

[tex]x = -7[/tex] and [tex]x = 2[/tex]

Step-by-step explanation:

Given

See attachment for graph

Required

Find x, for [tex]f(x)= 1[/tex]

From the graph, we have the following readings

[tex]f(x)= 1[/tex] when:

[tex]x = 2[/tex] and [tex]x = -7[/tex]

Hence, (d) is correct

Answer:

Expression: 7+7+9.5+6+9.5

Evaluation: 39 cm

Step-by-step explanation:

Let's write the numerical expression for the figure to the right. The perimeter is the addition of all sides of the figure. Therefore, we write 7+7+9.5+6+9.5 for our expression.

Now, to evaluate the expression, we just add them together. 7+7+9.5+6+9.5=39 cm.

Answer:

b

Step-by-step explanation:

ax^2+bx+c=0

1/2x^2-3x-2=0

Answer:

B

Step-by-step explanation:

Answer:

16×14 = -9×(-8) = -13×7

Falso

Step-by-step explanation:

A cylinder is a three-dimensional structure formed by two parallel circular bases connected by a curving surface. The correct option is A.

A cylinder is a three-dimensional structure formed by two parallel circular bases connected by a curving surface. The circular bases' centers overlap each other to form a right cylinder.

The solid is described as a three-dimensional solid made from

two parallel and congruent discs, not in the same plane, and all the points

between them is a Cylinder.

Hence, the correct option is A.

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Answer:

x = 20

y = 10

Answered by Gauthmat

Taking into account the definition of axis of simmetry and vertexn the axis of symmetry is x = 5.

So, first of all, you must know what a quadratic function is. Every quadratic function can be expressed as follows:

f(x) = a*x² + b*x + c

where a, b and c are real numbers.

The graph of a quadratic function is a parabola. Every parabola is a symmetric curve with respect to a horizontal line called the axis of symmetry.

That is, the axis of symmetry is an imaginary line that passes through the middle of the parabola and divides it into two halves that are equal of each other.

In other words, the axis of symmetry of a parabola is a vertical line that divides the parabola into two equal halves and always passes through the vertex of the parabola.

The point of intersection of the axis of symmetry with the parabola is called the vertex.

The axis of symmetry always passes through the vertex of the parabola. The x-coordinate of the vertex is the equation of the axis of symmetry of the parabola.

Being the vertex of the quadratic function (5,7), where the vertex on the x-axis has a value of 5 and on the y-axis a value of 7, the axis of symmetry is x = 5.

Learn more with this examples:

Answer:

x = 4

Step-by-step explanation:

3x+8x=13+31

Combine like terms

11x =44

Divide by 11

11x/11 = 44/11

x = 4

The answer you are looking for is x=4.

Solution:

3x+8x=13+31

Combining and adding similar terms,

11x=44

Dividing both sides by 11,

So, therefore,

The final answer is x=4.

Answer:

A=a+b

2

Step-by-step explanation:

To find the area of a trapezoid, multiply the sum of the bases (the parallel sides) by the height (the perpendicular distance between the bases), and then divide by 2.

[tex] \begin{cases}\large\bf{\green{ \implies}} \tt \: \frac{6}{5} \: k \: = \: 12 \\ \\ \large\bf{\green{ \implies}} \tt \: \frac{6k}{5} \: = \: 12 \\ \\ \large\bf{\green{ \implies}} \tt \: 6k \: = \: 12 \: \times \: 5 \\ \\ \large\bf{\green{ \implies}} \tt \: 6k \: = \: 60 \\ \\ \large\bf{\green{ \implies}} \tt \: k \: = \: \cancel\frac{60}{6} \\ \\ \large\bf{\green{ \implies}} \tt \: k \: = \: 10 \end{cases}[/tex]

Answer:

k = -10

Step-by-step explanation:

In order to solve for k, we need to isolate the variable. This means we need k to be on one side of the equation by itself.

We are given:

[tex]-\frac{6}{5}k=12[/tex]

The first thing I would do is multiply both sides of the equation by 5:

[tex](5)-\frac{6}{5}k=12(5)[/tex]

This leaves us with:

[tex]-6k=60[/tex]

Now, in order to get k by itself, we need to divide by -6 on both sides:

[tex]\frac{-6k}{-6}=\frac{60}{-6}[/tex]

Therefore:

[tex]k=-10[/tex]

Answer:

Hi there! The answers will be in the explanation :D

Step-by-step explanation:

a) I'll attach a doc for the table so it'll basically answer a and b.

c) I'll also attach the graph.

d) I'm not entirely sure for this question, but I'll do my best to answer it correctly for you. I would say no, because we can see that the residuals are all positive, but the graph we're looking is going down which means it's negative. We can also see the table is increasing a bit so it doesn't really make any sense...

Hope this helped you!

Answer:

b

Step-by-step explanation:

2x4=8 3x2=6 2x2=4

there all diviseble by 2

therfore ur answer is b

Answer:

the answer is 4

Step-by-step explanation: