Question

Simplify the following expressions:
1) (x + y + z) (x + y - Z)​

Answer 1

Answer:

Step-by-step explanation:

(x +y + z ) ( x + y - z )

= [ ( x+ y) +z ] [ (x +y ) - z ]

= ( x + y )^2 - z^2 because (a+b)(a-b)=a^2-b^2

= x^2+ y^2+ 2xy- z^2

[ because (a+b)^2 = a^2 + b^2 +2ab]

= x^2 + y^2 - z^2 + 2xy