(x-3) , (x+5) , (x+3) , (x-5)

Question

Find the product of all 4 binomials.

Answer 1

(x^2-9)(x^2-25)

= x^4 -34x^2 + 225

x-3 and x+3 are conjugate pairs

same with x-5 and x+5

they're of the form (a-b)(a+b) = a^2 -b^2 where a=x and b = 3 in the 1st pair and 5 in the 2nd pair

Use FOIL to expand the 2 quadratic factors to get a 4th degree trinomial