括号里填什么?3x^2-2x+1-()=5x-6(^2=2次方)

问题描述:

括号里填什么?3x^2-2x+1-()=5x-6(^2=2次方)

3x^2-2x+1-(3x^2-7 x+7)=5x-6
()=3x^2-2x+1-5 x+6
=3x^2-7 x+7