(12a-b)2 степень-(9а-b) (16а+2b)=
(12a-b)^2 - (9a-b)(16a+2b) = 144a^2 - 24ab + b^2 - (144a^2 + 2ab - 2b^2) = 144a^2 - 24ab + b^2 - 144a^2 - 2ab + 2b^2 = 3b^2 - 26ab