解下列方程组:(1){x-3y=2 2x+y=18 (2){2a+b=0 4a+3b=6 (3) {x-3y+20=0
解下列方程组:(1){x-3y=2 2x+y=18 (2){2a+b=0 4a+3b=6 (3) {x-3y+20=0
解下列方程组:(1)x=3y,2x-y=5 (2)2a+7b=5,3a+b=-2
解下列三元一次方程组; 1.2x+y=4,x+3z=1,x+y+z=7.2.a+b+c=0,4a+2b+c=3,a-b+
用代入法解下列方程组: (1){y=x+1,2x-3y;
用代入法解下列方程组{5x-2y=-2,{2a=-3b 3a-2b=5{2x+3y=40 x-y=-5 {2x+3y=4
解下列方程组{x=y-2/y-1{2x=(3/y+2)+1
解下列方程组{3x+7y=6,2x-7y=4;(2){y=3x,2x+3y=22.
用代入法解下列方程组{x-y-6,2x+3y-8 {3(y-2)=x-17,2(x-1)-5y-8
解下列方程组:x+2=3y,2x=3y.解下列方程组:3x+y=7,5x-2y=8.
用代入法解下列二元一次方程组 (1){x+5y=6,3x-6y=4 (2){5x-2y=-2,x+3y=3 (3){2a
解下列方程组(1){y=1-x,4x-3y=5 (2){2x-y=3,3x+y-1=0 (3)2x+3y=-4,2x-4
解下列方程组(1){y=1-x,4x-3y=5 (2){2x-y=3,3x+y-1=0 (3){2x+3y=-4,2x-