Question

Factories 3( r+s )² - 5( r+s)² + 1​

Answer 1

3(r+s)² - 5(r+s)²+1

=( 3r+3s)² - (5r+5s)² + 1

using a²-b = (a+b)(a-b),

((3r+3s)-(5r+5s))((3r+3s)+(5r+5s)

=(3r+3s-5r-5s)(3r+3s+5r+5s)