Question

Expand using proper identities: ☺

(3x^2 + ax + b)(3x^2 - ax - b)​

Answer 1

(3x^2 +ax+b)(3x^2-( ax+ b))

(a+b)( a- b) = a^2 - b^2

( 3x^2)^2 - ( ax+b)^2

9 x^4 - a^2x^2 - b^2 - 2axb