数学书p118-4都算出繁分数了,题一：{4(x-y-1)=3(1-y)-2 和1 x/2+y/3=2题二2(x-y)/

数学书p118-4都算出繁分数了,题一：{4(x-y-1)=3(1-y)-2 和1 x/2+y/3=2题二2(x-y)/ 求解;一 (x-8y)(x-y) 二 (Y+2)(Y-2)-(Y-1)(Y+5) 三 (3X+4)(3X-4)-(2X+ {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 解方程组一{2x-5y=1,5x+2y=17 二{x+y/2=6-x-y/3,4(x+y)-5(x-y)=2 数学书解方程组{2(x+y)-(x-y)=3,（x+y)-2(x-y)=1 解方程组3(x+y)-4(x-y)=4和(x+y)/2+(x-y)/6=1 已知X和Y满足3X+4Y=2,X-Y-1/7 已知x=1/3,y=-1/2,求代数式x-(x+y)+(x+2y)-(x+3y)+(x+4y)-(x+5y)+...-( [(2x+y)^2+(y+2x)(y-2x)-2y(4x-y)]/4y,其中x=1/2,y=1/3 先化简,再求值：[(x+y)(x-y)-(x-y)^2+2y(x-3y)]/(-4y),其中x=1,y=-2 己知x平方+3xy一4y平方=0(y≠0)求代数式(1)y分之x(2)x+y分之x一y