若x-(5+2y)=12,则3x-6y=

若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 若5x+3y=3x+4y=x+2y+6,则x+y=___ 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若x-2y=5,则式子12-x+2y=.以知3x-4y=2x+y则x∶y= 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 若|5x+2y-12|+（3x-2y-6）平方=0,则x+2y=? 若(5X+2Y-12)(5X+2Y-12)+|3x+2y-6|=0,则2x+4y=? 若|5x+2y-12|+（3x+2y-6）（3x+2y-6）=0,则2x+4y= (5)若x/2=y/3(y不为0）则x/y=____,x+y/y=___,y/x-y=___. 若2x=3y,则(x*x+y*y)/x*x=? 解方程组：x+y/2+x-y/3=6 4(x+y)-5(x-y)=12 若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ 2(x-2y)²-7(x-2y)³+3(2y-x)²+(2y-x)³合并同类项 这个式子2（x-2y)²-7（x-2y)³+3(2y-x)²-(2y-x)³=2（x-2y)²-7（x-2y)³+3(x-2y)²+(x-2y)³=5(x-2y)²-6(x-2y)³=(x-2y)²(5-6x+12y) 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 若x^2-y^2=6 x+y=3 则x-y=多少 若(3x-2y)/(x+y)=2/3,则3x/5y=