{ 3(2x-y)+4(x-2y)=87 2(3x-y)+3(x-y)=142

问题描述:

{ 3(2x-y)+4(x-2y)=87 2(3x-y)+3(x-y)=142

3(2x-y)+4(x-2y)=876x-3y+4x-8y=8710x-11y=87.190x-99y=783.22(3x-y)+3(x-y)=142 6x-2y+3x-3y=142 9x-5y=142 90x-50y=1420.33式-2式得49y=637y=13将y=13代入1得10x-11y=8710x-11*13=8710x-143=8710x=230x=23...