Làm giúp em câu 3+4 trắc nghiệm và bài 2+3 ạ

Answer:

2.5 meter

Step-by-step explanation:

in a right triangle, tan of an angle  = opposite side /adjacent side

tan 70° = x/ 0.9 , multiply both sides by 0.9

0.9 * tan 70° = x, solve on a calculator

x ≈ 2.5 m

Answer:

I don't really know sorry

Answer: y/y+x

Step-by-step explanation: Reduce the fraction at the bottom (1 - x/y) (1 + x/y) = 1 + x/y = simplify and you get y/y+x

Answer:

(x-6)^2+y=3

Step-by-step explanation:

The vortex of the parabola is (6,3). So the vertex equation is (x-6)^2+y=3

Answer:

-19 = b

Step-by-step explanation:

76 = -4b

Divide each side by -4

76/-4 = 4-b/-4

-19 = b

Answer:

b = -19

Step-by-step explanation:

76 = -4b

shift -4 to the left hand side and when you shift -4 divides 76

76/-4 = b

-19 = b

Answer:

y= -1/2x + 3

Step-by-step explanation:

A line that would be perpendicular to y=2x+17, means that the line has a negative reciprocal slope. So because the slope is 2 in the original equation, -1/2 would be the slope of the new line

so now, plug in the point (8, -1) into the point-slope formula

y-y1=m(x-x1)

y1= -1

x1= 8

m= -1/2

So,

y- -1= -1/2(x-8)

y+1=-1/2x + 4

Subtract 1 from both sides

y=-1/2x+3

Hi there!

[tex]\large\boxed{y = \frac{x + 4}{7}}[/tex]

f(x) = 7x - 4

Rewrite f(x) with y:

y = 7x - 4

Swap the x and y variables:

x = 7y - 4

Solve for y:

x + 4 = 7y

y = (x + 4)/7

Answer:

yes it is the 10th term in the series

Step-by-step explanation:

The nth term of a geometric sequence is

[tex]a_{n}[/tex] = a₁ [tex](r)^{n-1}[/tex]

where a₁ is the first term and r the common ratio

Here a₁ = 7 and r = [tex]\frac{a_{2} }{a_{1} }[/tex] = [tex]\frac{14}{7}[/tex] = 2 , then

[tex]a_{n}[/tex] = 7 [tex](2)^{n-1}[/tex]

Equate [tex]a_{n}[/tex] to 3584 and solve for n

7 [tex](2)^{n-1}[/tex] = 3584 ( divide both sides by 7 )

[tex]2^{n-1}[/tex] = 512 , that is

[tex]2^{n-1}[/tex] = [tex]2^{9}[/tex]

Since the bases on both sides are equal, both 2 , then equate the exponents

n - 1 = 9 ( add 1 to both sides )

n = 10

3584 is the 10th term in the series

Answer:

D

Step-by-step explanation:

time = 27 ÷ 3 × 2 = 9 × 2 = 18 minutes → D

Answer:

The answer is below

Step-by-step explanation:

You first divide 27/3

= 9

you divide it cause you know how many times you have done a lap every 2 minutes.

Now to find how long you took you times 9 by 2

= 18

Therefore Jose took 18 minutes to swim 27 laps

Answer:

Step-by-step explanation:

25*-30= -$750

Second: He sells 22 of those calculators for $35 each, so he is making money.

22*35= $770

Third: With the remaining three calculators, he must pay $2 each for returned calculators, so he is losing money again.

3*-2= -6

Add all the costs and sales together, and you get 770-750-6= $14 profit

However, the problem does not say if he gets his money back for the 3 returned calculators. In that case if he did, you would add the cost of each of those calculators to his profit. 30*3= 90

$90+$14= $104 profit

here u go

Answer:

I hope this helps!

Answer:

12 mathletes is needed to solve 30 problems in 5 minutes

Step-by-step explanation:

8 athletes can solve 20 problems in 10 minutes

30-20=10

now we need 10 more problems to be solved so

20/2=10. 8/2=4 so we need more 4 mathletes to solve all the problems

Answer: a rectangular poster has an area of 260 square inches.the width of the poster is greater than 10 inches and is a prime number

Step-by-step explanation: a rectangular poster has an area of 260 square inches.the width of the poster is greater than 10 inches and is a prime number.what is the width

I would go with C as a first step

The correct answer is C (that is equating f(x) and g(x))

A quadratic polynomial has highest degree 2 and a linear polynomial has highest degree 1.

In geometric sense, solving them means finding the point of intersection of curves:

In X-Y plane, these polynomials can be written as:

[tex]y=-x^{2} +2x+3\\y=-2x+3[/tex]

Taking the value of y from second equation and substituting it in first equation we get,

[tex]-x^{2} +2x+3=-2x+3[/tex]

Therefore, with the above procedure, we got the first step of solving the equations with the help of substitution.

To know more about polynomials refer to:

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Answer:

M = sin ^-1 (5/11)

M = 27 degrees

Step-by-step explanation:

Since this is a right triangle, we can use trig functions

sin theta = opp / hyp

sin M = 5/11

Taking the inverse sin of each side

sin ^-1 sin M = sin ^-1 (5/11)

M = sin ^-1 (5/11)

M=27.03569

To the nearest degree

M = 27

Answer:

1) a³b⁴/ ab³ = a²b

2)2 (x³ )² = 2x^6

3)3x*2x³ y² = 6x⁴y²

Answer:

73

Step-by-step explanation:

Answer:

[tex]h^{-1}[/tex] (t) = [tex]\frac{7-t}{6}[/tex]

Step-by-step explanation:

let y = h(t) and rearrange making t the subject

y = - 6t + 7 ( add 6t to both sides )

6t + y = 7 ( subtract y from both sides )

6t = 7 - y ( divide both sides by 6 )

t = [tex]\frac{7-y}{6}[/tex]

Change y back into terms of x with t = [tex]h^{-1}[/tex] (t)

[tex]h^{-1}[/tex] (t) = [tex]\frac{7-t}{6}[/tex]

Answer:

jejejjejejr

Step-by-step explanation:

uejejjejejjsjs

Answer:

y = 3x-10

Step-by-step explanation:

When lines are parallel, they have the same slope

y = 3x+2 is in slope intercept form

y = mx+b where m is the slope and b is the y intercept

The slope is 3

y = 3x+b

We have a point on the line

-1 = 3(3)+b

-1 = 9+b

-10 = b

y = 3x-10

Answer:

O I, II, and III only

Step-by-step explanation:

x-3 < 2

Add 3 to each side

x-3+3< 2+5

x<5

-3 is less than 5

0 is less than 5

2 is less than 5

5 is not less than 5

I , II , II are true

Answer:

5 < x < 21

Step-by-step explanation:

I did this bfore.

Answer:

Therefore 3/10 is closer to ½

Step-by-step explanation:

We've to get the difference:

» with 3/10 :

[tex] \frac{1}{2} - \frac{3}{10} = { \boxed{\frac{1}{5} }}[/tex]

» with 5/7

[tex] | \frac{1}{2} - \frac{5}{7} | = { \boxed{ \frac{3}{14} }}[/tex]

but:

[tex] \frac{3}{14} > \frac{1}{5} [/tex]

Among both the given fractions, the one that is closer to a ½ is 3/10.

A number that is stated as a quotient in mathematics, when the numerator and denominator are split in half. Both are integers in a straightforward fraction. In the numerator or denominator of a complex fraction is a fraction.

An element of a whole or, more broadly, any number of equal pieces, is represented by a fraction. When used in conversational English, a fraction indicates the number of components of a particular size, as in one-half, eight-fifths, and three-quarters.

A fraction is a number that represents a portion of a whole. In order to evaluate it, a whole is divided into a number of components.  A correct fraction has a numerator that is lower than its denominator.

Required calculations are done with both the fractions,

1/2 - 3/10 = 1/5

1/2 - 5/7 = 3/14

3/14 ≥ 1/5

Therefore, among both the given fractions, the one that is closer to a ½ is 3/10.

Learn more about fraction from here:

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Answer:

25%

Step-by-step explanation:

1 dozen = 12

3 out of 12

3/12

Simplify

1/4

Multiply top and bottom by 25 to get a denominator of 100

25/100

25%

Answer:

(a square +7a+12) ÷(a+3)

Answer:

10

Step-by-step explanation:

1) The vector CD is equal to (X-(-14); 13-6)= (x+14; 7)

2) The module of the vector CD is equal to diatance CD=25. It is equal to

 sqrt ((x+14)(x+14)+7*7) from the formula of module (with coordinates).

25= sqrt ((x+14)(x+14)+7*7)

625= (x+14)*(x+14)+49

625= x^2+28x+196+49

X^2+28X-380=0

a=1 b=28 c=-380

D= b*b-4ac= 28*28-4*1*(-380)= 784+1520= 2304

sqrt D= sqrt2304=48

x1= (-28-48)/2= -38

x2= (-28+48)/2= 10

But x1<0 it is negative and it is not suitable, x2>0 it is positive, so answer is 10.

Answer:

Option D, 52

Answered by GAUTHMATH

Answer:

x > 5

Step-by-step explanation:

-5-7x < -40

Add 5 to each side

-5+5-7x < -40+5

-7x < -35

Divide by -7, remembering to flip the inequality

-7x/-7 > -35/-7

x > 5

Open circle at 5, going to the right