整式的加减计算题及答案 快快快快快快快快快快
2个回答

1 (x²+5+4x)+(5x-4+2x²)

=x²+5+4x+5x-4+2x²

=(x²+2x²)+(4x+5x)+(5-4)

=3x²+9x+1

2 7x-(5x-5y)-y

=7x-5x+5y-y

=2x+4y

3 2x-(3x-2y+2)+(3x-4y-1)...