1>若x-y=5,则14-2x+2y=?2>已知丨x+5y-6丨+（3x-6y-4）的平方=0,则（x+y）=?3>10+20+30.+180+190+200=?1>2>过程,

若5x+y/7x+10y=1/2,则x/y=? 若7x+10y分之5x+y=1/2,则x/y= 若（5x+y）／(7x+10y)=1/2则x/y= x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 若2/x-1/y=3,求[y/x-y/x-y(x-y/x-x+y)]/x-2y/x的值 若3x-5y=0,则x+y/x=（）,x-y/y=（）,2x-3y/2x+3y=( ) 若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 若f(x+y,y/x)=x^2-y^2,则F(X,Y)= 若(x-y)/(x+y)=3 则(x+2y)/(6x-7y)等于 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 若x*x+y*y=x+y-1/2,求x,y的值如题 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 (5)若x/2=y/3(y不为0）则x/y=____,x+y/y=___,y/x-y=___. 若x+y=1,x不等于0则x+(2xy+y^2)/x/(x+y)/x= {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=?