方程组 0.8x-1.7y=-7 ,5x-3y=2

解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6 解下列方程组:x+2=3y,2x=3y.解下列方程组：3x+y=7,5x-2y=8. 方程组 x+5y+2=06x-7y=16x=y= 方程组x-2y=8,3x-4y=5,x=?,y=? y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组, 换元法解方程组3/x+y+2/x-y=17/5 2/x+y-5/x-y=1 2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 解方程组 解方程组﹛2(x+y)-3(x-y)=1 6(x+y)+7(x-y)=51 x+y/2+x-y/3=6,4(x+y)-5(x-y)=2用加减消元法解方程组 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 解方程组 解方程组 {(x+y)/2+(x-y)/3=6 5(x+y)-2(x-y)=4