Question

express (x^2+5x+12)(x^2-5x+12) as a different of two square

Answer 1

Let x^2 be a and 5x+12 be b.

(x^2)^2 - (5x+12)^2 [(a+b)(a-b)=a^2-b^2]

x^4 - [(5x)^2 + (12)^2 + 120x]

x^4-25x^2-144-120x