合并同类项,并去括号 (x2-y2)-4(2x2-3y)(x2-y2)-4(2x2-3y)7a+3(a+3b)3x-(4y-2y+_数学解答

合并同类项,并去括号 (x2-y2)-4(2x2-3y)
(x2-y2)-4(2x2-3y)
7a+3(a+3b)
3x-(4y-2y+1)

人气：494 ℃　时间：2020-06-23 01:14:24

解答

(x2-y2)-4(2x2-3y)
=x²-y²-8x²+12y
=-7x²-y²+12y
7a+3(a+3b)
=7a+3a+9b
=10a+9b
3x-(4y-2y+1)
=3x-2y-1