Question

(5-x)(5+x)
(a-4b)(a+b)

Answer 1

(5-x)(5+x)
25+5x-5x-x^2
25+0-x^2
25-x^2
-x^2+25

(a-4b)(a+b)
a^2+ab-4ba-4b^2
a^2-3ab-4b^2
-3ab+a^2-4b^2
a^2-3ab-4b^2