已知2/3x-1=1/2x+1/5,求5x²-[3x-x(2x-3)+7x²]的值

2/3x-1/2x=1/5+1
1/6x=6/5
x=36/5
5x²-[3x-x(2x-3)+7x²]
=5x²-3x+x(2x-3)-7x²
=-2x²-3x+2x²-3x
=-6x
=-6×36/5
=-216/5