(7x+2y)+(4+3x)-(15y-7) 5(x+y)-4(3x-2y)-3(2x-3y) 等于多少 两道合并同类项的题

(7x+2y)+(4+3x)-(15y-7)
=7x+2y+4+3x-15y+7
=(7x+3x)+(2y-15y)+(4+7)
=10x-13y+11
5(x+y)-4(3x-2y)-3(2x-3y)
=5x+5y-12x+8y-6x+9y
=(5x-12x-6x)+(5y+8y+9y)
=-13x+22y

(7x+2y)+(4+3x)-(15y-7)
=7x+2y+4+3x-15y+7
=10x-13y+11
5(x+y)-4(3x-2y)-3(2x-3y)
=5x+5y-12x+8y-6x+9y
=-13x+22y