Fill in the blanks to make the equation true.

Question

Fill in the blanks to make the equation true.

(x−9)(x+2)=x2________ −18

Answer 1

Hi Kiranpreet.

 

We call the method to multiply  (x-9)(x+2)  "FOIL"ing. 

 

This means

First  (x * x ) = x²

Outer (x * 2 ) = 2x

Inner ( x * (-9) ) = -9x

Last  ((-9) x 2 ) = -18

 

All in a row, this is

 

x² + 2x - 9x - 18

 

Combine like terms:

 

x² -7x - 18

 

The expression that goes on the blank line is:    -7x