Question

Calcule :
a) (2+x) (2-x)=
b) (w-5) (w+5)=
c) (r-s) (r+s) =

Answer 1

a) (2+x) (2-x)=

4 - 2x + 2x - x²

-x² + 4

b) (w-5) (w+5)=

w² + 5w - 5w - 25

w² - 25

c) (r-s) (r+s) =

r² + rs - rs - s²

r² - s²