7.6x201.3+0.43x2013-19x20.13
=2013x(0.76+0.43-0.19)
=2013x(0.76+0.24+0.19-0.19)
=2013x1
=2013X，Y满足2X+Y=6，X-3Y=1，7Y（x-3y）的2次方-2（3y-x）的3次方你好，7y(x-3y)^2-2(3y-x)^3=(x-3y)^2(7y-6y+2x)=(x-3y)^2(y+2x)=1*6=6