3(a-b)²-7(a-b)+8(a-b)²+6(a-b),其中a-b=2.怎么写求解,

问题描述:

3(a-b)²-7(a-b)+8(a-b)²+6(a-b),其中a-b=2.怎么写求解,

3(a-b)²-7(a-b)+8(a-b)²+6(a-b),
=11(a-b)²-(a-b)
当a-b=2时原式=11*4-2=42