(6a-3b)²+(9a+2b)²=36a²-36ab+9b²+81a²+36ab+4b²=117a²+13b² b(b-3)-(b-4)²=b²-3b-(b²-8b+16)=b²-3b-b²+8b-16=5b-16 (12-b)²-(9a-b)(16a+2b)=144-24b+b²-(144a²+18ab-16ab-2b²)=
144-24b+b²-144a²-18ab+16ab+2b²=144-24b+3b²-144a²-2ab x(2x-9)²-2x(15+x)² =x(4x²-36x+81)-2x(225+30x+x²)=
4x³-36x²+81x-450x-60x²-2x³=2x³-96x²-369x
(6a-3b)²+(9a+2b)²=36a²-36ab+9b²+81a²+36ab+4b²=117a²+13b²
b(b-3)-(b-4)²=b²-3b-(b²-8b+16)=b²-3b-b²+8b-16=5b-16
(12-b)²-(9a-b)(16a+2b)=144-24b+b²-(144a²+18ab-16ab-2b²)=
144-24b+b²-144a²-18ab+16ab+2b²=144-24b+3b²-144a²-2ab
x(2x-9)²-2x(15+x)² =x(4x²-36x+81)-2x(225+30x+x²)=
4x³-36x²+81x-450x-60x²-2x³=2x³-96x²-369x