2道因式分解、急~
问题描述:
2道因式分解、急~
1.(x+1)²-9(x-1)²
2.4a²b²-(a²+b²-c²)²
答
1.(x+1)²-9(x-1)²=[(x+1)+3(x-1)][(x+1)-3(x-1)]=(4x-2)(-2x+4)=-4(x-2)(x-2)=-4(x-2)²2.4a²b²-(a²+b²-c²)²=[2ab+(a²+b²-c²)][2ab-(a²+b...