Question

1- (x+5)² - (x + 5) (x - 5) = 0
2- (x - 5)² - (x + 5)² = 0

Answer 1

1-) x²+10x+25-(x²-5x+5x-25)=0
x²+10x+25-x²+5x-5x+25=0
10x=-25-25
x=-50/10
x=-5

2-) x²-10x+25-(x²+10x+25)=0
x²-10x+25-x²-10x-25=0
-20x=0
x=0/-20
x=0

Answer 2

a)

(x + 5)² - (x + 5).(x - 5) = 0
x² + 2.5x + 25 - (x² - 25) = 0
x² + 10x + 25 - x² + 25 = 0
10x + 50 = 0
10x = - 50  (:10)
x = - 5

b)
(x - 5)² - (x + 5)² = 0
x² - 2.5x + 25 - (x² + 2.5x + 25) = 0
x² - 10x + 25 - (x² + 10x + 25) = 0
x² - 10x + 25 - x² - 10x - 25 = 0
x² - x² - 10x - 10x + 25 - 25 = 0
- 20x = 0
x = 0