Question

При а=-3, b=3, (3а-b)(4b-9a)-(2b+3a)^2

Answer 1

5ab^2-5a^3=5a(b^2-a^2)=5a(b-a)(b+a)=-20*1*(-7)=140

Answer 2

(3a-b)(4b-9a)-(2b+3a)²=12ab-27a²-4b²+9ab-4b²-12ab-9a²=-36a²+9ab-8b²
-36*(-3)²+9*3*(-3)-8*3²=-36*9+9*(-9)-8*9=-324-81-72=-477