First square the binomial below, place it into perfect square trinomial form, and then subtract the trinomials.

Question

(7b2 - 7) 2 - (2b2 - 11) 2

Answer 1

(7b² - 7)² - (2b² - 11)² = (7b² - 7)*(7b² - 7) - (2b² - 11)*(2b² - 11) =

= ( 7b² * 7b² + 7b² *(-7) + (-7) * 7b² + (-7)*(-7) ) - ( 2b² * 2b² + 2b² * (-11) + (-11) * 2b² + (-11) * (-11) )

= (49b⁴ - 98b² + 49) - (4b⁴ - 44b² + 121)

= b⁴ (49-4) + b² (-98 + 44) + (49 - 121) = 45b⁴ - 54b² - 72