1,9(2a+3b)^2-4(3a-2b)^2 2,已知x+3y=0,求x^3+3x^2y-2x-6y的值
问题描述：
1,9(2a+3b)^2-4(3a-2b)^2 2,已知x+3y=0,求x^3+3x^2y-2x-6y的值
答
1,9(2a+3b)^2-4(3a-2b)^2 =(6a+9b)²-(6a-4b)²=(6a+9b+6a-4b)(6a+9b-6a+4b)=(12a+5b)*13b=13b(12a+5b)2,已知x+3y=0,求x^3+3x^2y-2x-6y的值x^3+3x^2y-2x-6y=x²(x+3y)-2(x+3y)=(x²-2)(x+3y)=(x...