Which of the following is equivalent to the expression below?
Square root of -81
A. 9
B. -9
C. 9i
D. -9i

Answer:

the first one is 3.7 x 10^-4

and the second one is 3.7 x 10^4

explanation:

when we have decimals we are going backward,

therefore "0.00037" would be a negative number

to find the scientific notation form, we have to move the decimal over to the left untill we get 3.7

it took 4 moves to the right to get to 3.7, and since were dealing with decimals it will be negative,

so the first one is 3.7 x 10^4

the second one however is not a decimal so it will be a positive exponent.

now remember that there is always a decimal after a number we might just not see it.

so, going from the very end of the number it takes us 4 moves to the left to get to 3.7

so,

the second one will be 3.7 x 10^4

hope this helped :)

Answer:

21

Step-by-step explanation:

All three sides are equal

2x-7 = x+y-9 = y+5

Using the last two

x+y-9 = y+5

Subtract y from each side

x+y-9-y = y+5-y

x-9 = 5

Add 9 to each side

x -9+9 = 5+9

x=14

We know the side length is

2x-7

2(14) -7

28-7

21

The side length is 21

Answer:

30 and 270 respectively

Step-by-step explanation:

Let the speed of plane in still air be x and the speed of wind be y.

ATQ, (x+y)*4=1200 and (x-y)*5=1200. Solving it, we get x=270 and y=30

Answer:

850,000

Step-by-step explanation:

Answer: 850,000

Concept:

Here, we need to know the order and name of each place value.

Please refer to the attachment below for the specified names.

Solve:

8 = Hundred thousands

4 = Ten thousands

9 = One thousands

7 = Hundreds

0 = Tens

9 = Ones

Since the values before the ten thousands place, which would be the one thousands place, is greater than 5, then we should round up.

Therefore, the rounded value would be [tex]\boxed{850,000}[/tex]

Hope this helps!! :)

Please let me know if you have any questions

Answer:

-2

Step-by-step explanation:

Perpendicular lines have slopes that are negative reciprocals

Take the slope of AB = 1/2

-1/(1/2)

-1 * 2/1

-2

The slope of a line perpendicular is -2

Answer:

The leading coefficient is -8 as it is a mix of x and cardinal, if it was x alone then it wouldn't be the coefficient, we would use the next number shown.

If it was just a number and no x then it would still be the coefficient.

The degree is 9 as it is the highest power shown.

Step-by-step explanation:

See attachment for examples

Answer:

ask in English then I can help u

Answer:

-6

Step-by-step explanation:

a1= -3

r= -(3/2)/-3 = 0.5

r>-3

s= a1/1-r

= -3/1-0.5

=-6

Answer:

2 + 109 = 111

Step-by-step explanation:

.............

Answer:

B) Its final coordinates are (8,-6)

Step-by-step explanation:

1. Translated 1 unit up and 4 units left

(-2,7) becomes (-6, 8)

2. Reflected about the x-axis

(-6,8) becomes (-6, -8)

3. Rotated 90° anticlockwise about the origin

(-6, -8) becomes (8, -6) because when rotating 90 degrees anticlockwise about the origin, point A (x,y) becomes point A' (-y,x). In other words, switch the x and y and make y negative.

Answer:

d=8 and a=7

Step-by-step explanation:

The sum of a arithmetic sequence is given by (n/2)*(2a+(n-1)d). Comparing coefficients with the given Sn, we have; a-d/2=3 and d/2=4, d=8 and a=7. The sequence is 7, 15, 23, 31, 39

Answer:

the nullity of a matrix A is the demision of its null space:nullity A = dim (n(A).

Answer:

2019

Step-by-step explanation:

I am assuming you mean graduated from high school. If that's the case it's 2019. Sophmore year means 9th grade. which is 2019!

Answer:

48degrees

Step-by-step explanation:

From the circle geometry shown, traingle BDC is an isosceles triangle which shows means that their base angels are the same. Hence;

<B = <C

<CBD + <BCD + <D = 180

<BCD + <BCD + <D =180

2<BCD + <BDC = 180

Get <BCD;

<BCD+ <ECB = 90

<BCD + 48 = 90

<BCD = 90 - 48

<BCD = 42degrees

Get <BDC

2<BCD + <BDC = 180

2(42)+ <BDC = 180

84 + <BDC = 180

<BDC = 180 - 84

<BDC = 96

Since angle at the centre is twice that at the circumference, then;

<BAC = 1/2(<BDC )

<BAC = 96/2

<BAC = 48degrees

Answer:

incomplete question

Step-by-step explanation:

that is what is wrong with your question

Answer:

r = 4.3%

Step-by-step explanation:

6810= 6000(x)^3

6810/6000=  (x)^3

x = 1.043114431

r = 043114431

Answer: [tex]10,000\ lb.ft[/tex]

Step-by-step explanation:

Given

Initial weight of the bucket is [tex]145\ lb[/tex]

It is lifted at constant rate and rate of sand escaping is [tex]0.5\ lb/ft[/tex]

At any height weight of the sand is [tex]w(h)=145-0.5h[/tex]

Work done is given by the product of applied force and displacement or the area under weight-displacement graph

from the figure area is given by

[tex]\Rightarrow W=\int_{0}^{80}\left ( 145-0.5h \right )dh\\\\\Rightarrow W=\left | 145h-\dfrac{0.5h^2}{2} \right |_0^{80}\\\\\Rightarrow W=\left [ 145\times 80-\dfrac{0.5(80))^2}{2} \right ]-0\\\\\Rightarrow W=11,600-1600\\\\\Rightarrow W=10,000\ lb.ft[/tex]

9514 1404 393

Answer:

  4.8 years

Step-by-step explanation:

Solving the compound interest formula for the number of years gives ...

  t = log(A/P)/(n·log(1 +r/n))

where principal P invested at rate r compounded n times per year produces value A after t years.

  t = log(24805/22000)/(365·log(1 +0.025/365)) ≈ 4.800

The loan was for 4.8 years.

Answer:

The area of a triangle is:

Area = 1/2(bh)

Area = 1/2(70)

Area = 35 square inches

Let me know  if this helps!

Answer:

40141

Step-by-step explanation:

Answer:

GHC22.5

Step-by-step explanation:

90/3=30

30=0.75

30×0.75

=22.5

[tex]\\ \Large\sf\longmapsto h(t)[/tex]

[tex]\\ \Large\sf\longmapsto 2+8t-3t^2+\dfrac{1}{5}t^3[/tex]

[tex]\\ \Large\sf\longmapsto 2+8(3)-3(3)^2+\dfrac{1}{5}(3)^3[/tex]

[tex]\\ \Large\sf\longmapsto 2+24-3(9)+\dfrac{27}{5}[/tex]

[tex]\\ \Large\sf\longmapsto 26-27+5.4[/tex]

[tex]\\ \Large\sf\longmapsto -2+5.4[/tex]

[tex]\\ \Large\sf\longmapsto h(t)=3.4m[/tex]

Step-by-step explanation:

a) let number=x

four times a number=4x

Condition:

4x+6=50

4x=50-6

4x=44

x=44/4

x=11

b) Condition:

x+9×-2=-8

x-18=-8

x=-8+18

x=10

Note:if you need to ask any question please let me know.

Answer:

28 units²

Step-by-step explanation:

Area of trapezoid =

2(8 + 4)/2 = 12

Area of rectangle =

2 x 8 = 16

16 + 12 = 28

If my answer is incorrect, pls correct me!

If you like my answer and explanation, mark me as brainliest!

-Chetan K

Answer:

3. 6a+60

5. 25+5w

7. 90-10t

11. 4.5-12c

13. f-2

15. 12z+1.5

Step-by-step explanation:

3.

6(a+10)

Multiply 6 by both factors in the parentheses, in this case, a and 10.

6*a = 6a

6*10 = 60

6(a+10) = 6a + 60

I only put the step- by- step explanation for #3, but you should be able to figure the rest out with that.

Answer:

The height is 20 meters

Step-by-step explanation:

First set up the equation (Area)80=bh/2 then set up another equation, (height) h=4+2b (base). After this you can substitute h in the equation to end up with 80=(b(2b+4))/2 simplify it to get 80=b^2+2b then solve. The base is 8 meters, plug into the formula that we made before and you find the height is 20 meters.

Answer:

v-(-5)<-9

v- remove brackets -5

v- -5= -4 +5 ( opposite operation)

v- = -4

v< -4

Answer:

[tex]P(C'\ and\ H') =0. 2178[/tex]

Step-by-step explanation:

Let

[tex]C \to[/tex] Student with cat

[tex]H \to[/tex] Student has HBO sub

[tex]P(C) = 66\% \\ P(H) = 37\%[/tex]

Required

[tex]P(C'\ and\ H')[/tex]

This is calculated as:

[tex]P(C'\ and\ H') = P(C') * P(H')[/tex]

Using complement rules, we have:

[tex]P(C'\ and\ H') = [1 - P(C)] * [1 - P(H)][/tex]

So, we have:

[tex]P(C'\ and\ H') = [1 - 66\%] * [1 - 37\%][/tex]

[tex]P(C'\ and\ H') = [33\%] * [66\%][/tex]

[tex]P(C'\ and\ H') =0. 2178[/tex]