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19. The function f(x) = 27x – 67.5 has an

* -intercept at (a,0). The function g(x) is
defined in the table below and has an
x-intercept at (b,0). How much greater is the
value of b than the value of a?

19. The function f(x) = 27x – 67.5 has an * -intercept at (a,0). The function g(x-example-1
User Ruelluna
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5.2k points

1 Answer

4 votes

Answer:

First we have the function f(x) = 27*x - 67.5

It has an x-intercept at (a, 0)

This means that:

f(a) = 0 = 27*a - 67.5

Solving the above equation we can find the value of a.

0 = 27*a - 67.5

67.5 = 27*a

67.5/27 = a = 2.5

Now let's look at equation g(x).

It is a linear equation, remember that a linear equation can be written as:

g(x) = y = A*x + B

Where:

A is the slope, and B is the y-intercept.

If the line passes through the points (x₁, y₁) and (x₂. y₂), the slope can be written as:

A = (y₂ - y₁)/(x₂ - x₁)

In this case we can select any two points from the table, for example, I will use the second and third points:

(1, 39) and (2, 32.5)

Then the slope is:

A = (32.5 - 39)/(2 - 1) = -6.5/1 = -6.5

Then the equation is something like:

g(x) = y = -6.5*x + B

B is the y-intercept, to find this value, we can use one of the two points we used before.

For example, (1, 39) means that g(1) = 39

Then:

g(1) = -6.5*1 + B = 39

= B = 39 + 6.5 = 45.5

Then the equation for g(x) is:

g(x) = -6.5*x + 45.5

Now, we know that g(x) has an x-intercept at (b, 0)

this means that:

g(b) = 0 = -6.5*b + 45.5

6.5*b = 45.5

b = 45.5/6.5 = 7

Then the difference between b and a is:

b - a = 7 - 2.5 = 4.5

b is equal to a plus 4.5

And the ratio is:

b/a = 7/2.5 = 2.8

b is 2,8 times larger than a.

User Takema
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5.9k points