(3x²-2)-(4x²-2x-3)+(2x²-1)
=3x²-2-4x²+2x+3+2x²-1
=x²+2x
=(-2)²+2×(-2)
=4+(-4)
=03(a²-2ab)-（-ab+b²）求解题过程、-2（2x²-x+4）+3（x²-2x+3）求解题过程，谢了。请采纳后求助！