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Sergeeva-Olga [200]

3 years ago

6

A service call to repair a washing machine costs $35 plus $20 per hour. Raphael ‘s machine took 2 hour to fix. How much did the

repair cost ?
F. $50.00. G. $55.00. H. $65.00
I. $75.00

2 answers:

Lady bird [3.3K]3 years ago

5 0

There is a mandatory fixed rate of $ 35 that Raphael will have to pay once the service call has been made. This fixed rate is the constant.

The per hour rate is $20. Suppose the machine took "x" hours to get fixed. Then the variable part of the repair cost will be $20x$ .

Thus, Repair Cost=Fixed Rate Cost+Variable Cost

Or, $y=35+20x$ where $y$ is the total repair cost. Thus, if Raphael ‘s machine took 2 hour to fix, the repair cost is:

$y=35+20\times 2=35+40=75$ dollars.

Therefore, the last option is the correct option.

I am Lyosha [343]3 years ago

5 0

I. $75

Your equation would be 35 + 20x

X is the amount of hours it was fixed

35 + 20 x 2

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Harrizon [31]

Answer:

62.8cubic units

Step-by-step explanation:

volume of a cylinder isπ×radius×radius×height.hope it helps.

4 0

3 years ago

Scientists modeled the intensity of the sun, I, as a function of the number of hours since 6:00 a.m., h, using the

MAVERICK [17]

The functions are illustrations of composite functions.

<em>The soil temperature at 2:00pm is 67</em>

The given parameters are:

$\mathbf{I(h) =\frac{12h - h^2}{36}}$ ---- the function for sun intensity

$\mathbf{T(I) =\sqrt{5000I}}$ -- the function for temperature

At 2:00pm, the value of h (number of hours) is:

$\mathbf{h = 2:00pm - 6:00am}$

$\mathbf{h = 8}$

Substitute 8 for h in $\mathbf{I(h) =\frac{12h - h^2}{36}}$ , to calculate the sun intensity

$\mathbf{I(8) =\frac{12 \times 8 - 8^2}{36}}$

$\mathbf{I(8) =\frac{32}{36}}$

$\mathbf{I(8) =\frac{8}{9}}$

Substitute 8/9 for I in $\mathbf{T(I) =\sqrt{5000I}}$ , to calculate the temperature of the soil

$\mathbf{T(8/9) =\sqrt{5000 \times 8/9}}$

$\mathbf{T(8/9) =\sqrt{4444.44}}$

$\mathbf{T(8/9) =66.67}$

Approximate

$\mathbf{T(8/9) =67}$

Hence, the soil temperature at 2:00pm is 67

Read more about composite functions at:

brainly.com/question/20379727

5 0

2 years ago

3x + 9b + 5ax + 15ab

Irina-Kira [14]

Answer:

(x + 3b)(3 + 5a)

Step-by-step explanation:

Assuming you require the expression factorised.

Given

3x + 9b + 5ax + 15ab ( factor the first/second and third/fourth terms )

= 3(x + 3b) + 5a(x + 3b) ← factor out (x + 3b) from each term

= (x + 3b)(3 + 5a) ← in factored form

7 0

4 years ago

1. The height of a triangle is 6 m more than its base. The area of the triangle is 56 m². What is the length of the base? Enter

Elodia [21]

Answers:
1. 8 m
2. 17 m
3. 7 cm
4. 2 s

Explanations:

1. Let x = length of the base
x + 6 = height of the base

Then, the area of the triangle is given by

(Area) = (1/2)(base)(height)
56 = (1/2)(x)(x + 6)
56 = (1/2)(x²  + 6x)

Using the symmetric property of equations, we can interchange both sides of equations so that

(1/2)(x²  + 6x) = 56

Multiplying both sides by 2, we have

x² + 6x = 112

The right side should be 0. So, by subtracting both sides by 112, we have

x² + 6x - 112 = 112 - 112
x² + 6x - 112 = 0

By factoring, x² + 6x - 112 = (x - 8)(x + 14). So, the previous equation becomes

(x - 8)(x +14) = 0

So, either

x - 8 = 0 or x + 14 = 0

Thus, x = 8 or x = -14. However, since x represents the length of the base and the length is always positive, it cannot be negative. Hence, x = 8. Therefore, the length of the base is 8 cm.

2. Let x = length of increase in both length and width of the rectangular garden

Then,

14 + x = length of the new rectangular garden
12 + x = width of the new rectangular garden

So,

(Area of the new garden) = (length of the new garden)(width of the new garden)

255 = (14 + x)(12 + x) (1)

Note that

(14 + x)(12 + x) = (x + 14)(x + 12)
= x(x + 14) + 12(x + 14)
= x² + 14x + 12x + 168
= x² + 26x + 168

So, the equation (1) becomes

255 = x² + 26x + 168

By symmetric property of equations, we can interchange the side of the previous equation so that

x² + 26x + 168 = 255

To make the right side becomes 0, we subtract both sides by 255:

x² + 26x + 168 - 255 = 255 - 255
x² + 26x - 87 = 0

To solve the preceding equation, we use the quadratic formula.

First, we let

a = numerical coefficient of x² = 1

Note: if the numerical coefficient is hidden, it is automatically = 1.

b = numerical coefficient of x = 26
c = constant term = - 87

Then, using the quadratic formula

$x = \frac{-b \pm \sqrt{b^2 - 4ac} }{2a} = \frac{-26 \pm \sqrt{26^2 - 4(1)(-87)} }{2(1)} 
\newline x = \frac{-26 \pm \sqrt{1,024} }{2}
\newline
\newline x = \frac{-26 \pm 32 }{2}$

So,

$x = \frac{-26 + 32 }{2} \text{ or } x = \frac{-26 - 32 }{2}
\newline x = \frac{6 }{2} \text{ or } x = \frac{-58 }{2}
\newline \boxed{ x = 3 \text{ or } x = -29}$

Since x represents the amount of increase, x should be positive.

Hence x = 3.

Therefore, the length of the new garden is given by

14 + x = 14 + 3 = 17 m.

3. The area of the shaded region is given by

(Area of shaded region) = π(outer radius)² - π(inner radius)²
= π(2x)² - π6²
= π(4x² - 36)

Since the area of the shaded region is 160π square centimeters,

π(4x² - 36) = 160π

Dividing both sides by π, we have

4x² - 36 = 160

Note that this equation involves only x² and constants. In these types of equation we get rid of the constant term so that one side of the equation involves only x² so that we can solve the equation by getting the square root of both sides of the equation.

Adding both sides of the equation by 36, we have

4x² - 36 + 36 = 160 + 36
4x² = 196

Then, we divide both sides by 4 so that

x² = 49

Taking the square root of both sides, we have

$x = \pm 7$

Note: If we take the square root of both sides, we need to add the plus minus sign $(\pm)$ because equations involving x² always have 2 solutions.

So, x = 7 or x = -7.

But, x cannot be -7 because 2x represents the length of the outer radius and so x should be positive.

Hence x = 7 cm

4. At time t, h(t) represents the height of the object when it hits the ground. When the object hits the ground, its height is 0. So,

h(t) = 0 (1)

Moreover, since $v_0 = 27$ and $h_0 = 10$ ,

h(t) = -16t² + 27t + 10 (2)

Since the right side of the equations (1) and (2) are both equal to h(t), we can have

-16t² + 27t + 10 = 0

To solve this equation, we'll use the quadratic formula.

Note: If the right side of a quadratic equation is hard to factor into binomials, it is practical to solve the equation by quadratic formula.

First, we let

a = numerical coefficient of t² = -16
b = numerical coefficient of t = 27
c = constant term = 10

Then, using the quadratic formula

$t = \frac{-b \pm \sqrt{b^2 - 4ac} }{2a} = \frac{-27 \pm \sqrt{27^2 - 4(-16)(10)} }{2(-16)} \newline t = \frac{-27 \pm \sqrt{1,369} }{-32} \newline \newline t = \frac{-27 \pm 37 }{32}$

So,

$t = \frac{-27 + 37 }{-32} \text{ or } t = \frac{-27 - 37 }{-32} \newline t = \frac{-10}{32} \text{ or } t = \frac{-64 }{-32} \newline \boxed{ t = -0.3125 \text{ or } t = 2}$

Since t represents the amount of time, t should be positive.

Hence t = 2. Therefore, it takes 2 seconds for the object to hit the ground.

3 0

4 years ago

Read 2 more answers

Can somebody help me simplify these problems please?

Mazyrski [523]

1: answer: 4^6 ( reduce the fraction with 4^3)

2: answer: 1 ( any nonzero expression raised to the power of 0 equals 1 )

3: answer 3^8
steps: (3^2)^4 = 3^2×4 ( to raise a power to another Power multiply the exponents)
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7 0

3 years ago