Question

упростите выражение (3b-a)(2b-5a)-6(3a-b)²

Answer 1

( 3 b-a) (2b-5a)-6(9a²-6ab+b²)=6b²-15ab-2ab+5a²-54a²+36ab-6b²=19ab-49a²-6b²

Answer 2

(3b-a)(2b-5a)-6(3a-b)^2=(6b^2 + 5a^2)-6(9a^2 - 2*3a*b + b^2) = 6b^2 + 5a^2 - 6(9a^2 - 6ab + b^2) = 6b^2 + 5a^2 - 54a^2 + 36ab - 6b^2 = -49a^2 + 36ab