3x+6y=165和6x+3y=150.二元一次方程和一元一次方程,

(x-2y)(x+y)-2x(-2x-3y)+6x(-x-y),其中x=-1,y=2要讲解和答题 10x+y+3=6(x+y)则x和y各等于多少 解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1kkkkkkkk (2x-2y)/3-(x-y)=-1和6(x+y)-4(2x-y)=16 【2(x-y)^3-8(x-y)^2(x+y)+6y(x-y)^2】/2(x-y)^2= x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 2(x+y)-3(x-y)=1 6(x+y)+(x-y)=51 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/6=5 2(x+y)-3(x-y)=-2 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 （x+y）/2- x-y/2=6 3(x+y)=4(x-y) x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 6(x+y)的平方-11(x+y)(x-y)+3(x-y)的平方=? 已知方程组4X+3Y=6和3X+4Y=15,不解出X,Y,求(X+Y)除以(X-Y)的值. x+y/2+ x-y/2=6 2(x+y)-3x+3y=24 求X Y