(x-4)(x-4)=100

(x-4)(x-4)=x^2-8x+16.

 

The equation we have now is x^2-8x+16=100.

 

Subtract both sides by 100 so you can use the Zero Product Property: x^2-8x-84=0

 

x^2-8x-84 factored is (x-14)(x+6).

 

Using the Zero Product Property, we get x-14=0 and x+6=0.

 

x=14,-6.

 

Checking my work, I get 14-4 equals 10, 10 times 10 is 100.

 

-6-4 equals -10, -10 times -10=100.

x^2-4x-4x+16

simplified is x^2-8x+16

did ur teacher tell u about the foil method