1.解方程组6x+y=4① 6x-3y=-1② 可用①-②得到一元一次方程（ ） 2.方程组x+y=4 x-y=2的解是（ ）3.x=2 y=3 是方程2分之3 nx+my=4和mx-ny=3的公共解,则m=( ),n=( )4.一直两个数的和是15,这两个数的差是1,则这

3(x+y)—4(x-y)=4,(x+y/2)+(x-y/6)=1.解方程组 解方程组：｛4x+5(x-y)=30,4y-3(x-y)=6 解方程组,x+y/2=3x-2y=10+6x+y/4, 解方程组;x+y/2=x-y/3=6 4(x+y)-3(x-y)=-20 解二元一次方程组3(x+y)-4(x-y)=4 x+y/2+x-y/6=1 解方程组2(x-y)/3-x+y/4=-1 6(x-y)-4(2x-y)=16 解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1kkkkkkkk 解方程组3(x+y)-4(x-y)=4,x+y除以2+x-y除以6=1 解方程组：2(x-y)/3-x+y/4=-1 ,6(x+y)-4(2x-y)=16 解方程组⑴(x+y)/2-(x-y)/3=6,⑵3(x+y)=4(x-y) 解方程组 x-y/3-x+y/4=2 x-y/6-x+y/8=3 解方程组4（x+y)-3(x-y)=14;(x+y)/2+(x+y)/3=6 解方程组 X+Y/2+X-Y/3=6 4[X+Y]-5[X-Y]=2 解二元一次方程组{x+y/2+x-y/3=6,4(x+y)-2=5(x-y) 解二元一次方程组{3(x+y)-(x-y)=4,x+y/2+x-y/6=1 解方程组2分之x+y+3分之x-y=6 4(x+y)-5(x-y)=2 解方程组 {(x+y)/2+(x-y)/3=6 5(x+y)-2(x-y)=4 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12