【(y-2x)(-2x-y)-4(x-2y)的2次方乘(3y)ˇ2

【(y-2x)(-2x-y)-4(x-2y)的2次方乘(3y)ˇ2
【(y-2x)(-2x-y)-4(x-2y)的2次方乘(3y)ˇ2

【(y-2x)(-2x-y)-4(x-2y)的2次方乘(3y)ˇ2
[(y-2x)(-2x-y)-4(x-2y)的2次方]乘(3y)ˇ2 半个中括号?
=[(2x)²-y²-4(x²-4xy+4y²)]×(9x²)
=(4x²-y²-4x²+16xy-16y²)×(9x²)
=(16xy-17y²)×(9x²)
=144x³y-153x²y²