｛①(m+1)x-(3n+2)y=8②（5-n)x+my=11可以用①乘以2+②消去未知数x;也可以用①+②乘以5消去未知数y

①(m+1)x-(3n+2)y=8②（5-n)x+my=11由②得：y=[(n-5)x+11]/m *带入①得：(m+1)x-(3n+2)[(n-5)x+11]/m=8x=(33n+22+8m)/(m^2-m-3n^2+13n+10)带入*得：y=(33n^2-165n+22n-110+8mn-40m)/(m^3-m^2-3mn^2+13mn+10m)+11m所...