解方程组X+Y=200,5%x+50%y=200*30%

解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 5（x+y)+3(x-y)=90 5(x+y)-3(x-y)=30,解二元一次方程组 解方程组：（0.2x+0.1y）/2- （4x-y）/10=（x-y）/5+ (3x+0.5y)/30 (3x+2y-1 解关于X,Y的方程组 {x+y=a （a-1)x+y=5 阅读下面方程组的解法:解方程组{x/5=y/7,x+y=-36 解方程组:{二分之x+y+二分之x-y=6,4(x+y)-5(x-y)=2() 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 解方程组 解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6 解方程组:2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 解方程组：2/(x+y)+5/(x-y)=18 9/(x+y)-10/(y-x)=66 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