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What is the x intercept of the line? (-21,-64) (-15,-48) (-9,-32)

User NanoBot
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Answer:

The x intercept of the line is x = 9.

Explanation:

The equation of a line has the following format:


y = ax + b

In this question, we have three points. We can take two of them to build the equation.

(-15,-48)

This means that when x = -15 y = -48. So


y = ax + b


-48 = -15a + b

(-9,-32)

This means that when x = -9 y = -32. So


y = ax + b


-32 = -9a + b

From the first equation, we have that:


b = 15a - 48

Then


-32 = -9a + b


-9a + 15a - 48 = -32


6a = 16


a = (8)/(3)


b = 15a - 48 = (15*8)/(3) - 48 = (15*8 - 48*3)/(3) = -24

Then


y = (8x)/(3) - 24

What is the x intercept of the line?

The x intercept is x when y = 0. Then


(8x)/(3) - 24 = 0


(8x)/(3) = 24


8x = 24*3


x = 9

The x intercept of the line is x = 9.

User Camickr
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