用代入法解下列方程组{4x-2x=5,3x-4y=15 {2x=5(x+y),3x-10(x+y)=2

用代入法解下列方程组{4x-2x=5,3x-4y=15 {2x=5(x+y),3x-10(x+y)=2
用代入法解下列方程组{4x-2x=5,3x-4y=15 {2x=5(x+y),3x-10(x+y)=2

用代入法解下列方程组{4x-2x=5,3x-4y=15 {2x=5(x+y),3x-10(x+y)=2
因为4x-2x=5,所以2x=5,x=2.5.将x=2.5代入3x-4y=15得X=-15/8.
因为2x=5(x+y),所以2x=5X+5y,x=-5/3y.将x=-5/3y代入3x-10(x+y)=2得y=6/5