化简(过程清楚写出来）5a+(3x-3y-4a)3x-(4y-2x+1)7a+3(a+3b)(x²—y²）-4(2x²-3y)

化简(过程清楚写出来）5a+(3x-3y-4a)3x-(4y-2x+1)7a+3(a+3b)(x²—y²）-4(2x²-3y)
化简(过程清楚写出来）
5a+(3x-3y-4a)
3x-(4y-2x+1)
7a+3(a+3b)
(x²—y²）-4(2x²-3y)

化简(过程清楚写出来）5a+(3x-3y-4a)3x-(4y-2x+1)7a+3(a+3b)(x²—y²）-4(2x²-3y)
5a+(3x-3y-4a)
=5a+3x-3y-4a
=a+3x-3y
3x-(4y-2x+1)
=3x-4y+2x-1
=5x-4y-1
7a+3(a+3b)
=7a+3a+9b
=10a+9b
(x²-y²）-4(2x²-3y)
=x²-y²-8x²+12y
=-7x²-y²+12y

5a+(3x-3y-4a)=5a+3x-3y-4a=a+3x-3y
3x-(4y-2x+1)=3x-4y+2x-1=5x-4y-1
7a+3(a+3b)=7a+3a+9b=10a+9b
(x²—y²）-4(2x²-3y)=x²—y²-8x²+12y=-7x²—y²+12y