1,7Y+6=-6Y 2.2Y-3=7Y=7 3.0.5X-0.7=6.1-1.2X 4.1-3/2X+3X+5/2
x+y=3 x+2y=9 3/x+1=y y-x=3 y=2x-3 y-3x=1 2(x+1)-y=6 7x-5y=-9
若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
解二元一次方程组:{5(x+y)+3(x-y)=2{7(x+y)-3(x-y)=-6
6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5
若x、y满足2x+y=6,x-3y=1,求7y(x-3y)²-2(3y-x)³的值
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 y
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
7x-3y/5=5x-y/3-x+y/2 x-1/5=y+1/3
3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算
3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y
y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,