用因式分解解方程:9(x-1)²-(x+2)²=0
问题描述:
用因式分解解方程:9(x-1)²-(x+2)²=0
x²+10x+9=0
答
9(x-1)²-(x+2)²=0
9(x-1)²=(x+2)²
3(x-1)=x+2或3(x-1)=-x-2
3x-3=x+2或3x-3=-x-2
2x=5或4x=1
x=5/2或x=1/4