解方程组 7x-3y/5=5x-y/3-x-y/2 { x-1/5=y+1/3

解方程组{(x-2)(y+3)=(x+1)(y-1) {(x+1)(y+1)=(x-1)(y+5) 解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6 换元法解方程组3/x+y+2/x-y=17/5 2/x+y-5/x-y=1 10/x+y+3/x-y=-5 15/x+y-2/x-y=-1（用换元法解此方程组） 解二元一次方程组 x+y=3 1/2(x+y)-3y=5 解方程组: ｛3x+2y=13 3x-2y=5 ｛x-y/3=x+y/2+1 2x-5y=9 解方程组：（0.2x+0.1y）/2- （4x-y）/10=（x-y）/5+ (3x+0.5y)/30 (3x+2y-1 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 解方程组1.x+1/3=5x-y/5 7y=5x+25 (x=2,y=5) 2.2x-y/5=x+y/3=3(x=8,y 解方程组{x=2y,x+y=3; {y=1-x,3x+2y=5 ;{3x+5y=5,3x-4y; {2分之x-3分之y+ 1/2x-2y=-74,x-6y=-12解方程组,x／5-y／2=2,2x+3y=4解方程组 不解方程组{2x+y=5,x-3y=1,求7y(x-3y)²-2(3y-x)³的值