1) а²-b²-6a+6b = a(a-6) -b(b-6)
2) 1. (x+8y)(8y-x)=-x²+64y²
2. 3a(a+b)-(a+9)²=3a²+3ab-a²-18a-81=2a²+3ab-18a-81
1) а²-b²-6a+6b = a(a-6) -b(b-6)
2) 1. (x+8y)(8y-x)=-x²+64y²
2. 3a(a+b)-(a+9)²=3a²+3ab-a²-18a-81=2a²+3ab-18a-81