2x:3=x:7 2(y/3-1)=4(y/3-1)-1
已知x-y=1,y≠0,求{(x+2y)²+(2x+y)(x+4y)-3(x+y)(x-y)}÷y的值.
计算:1/(x-y)-1/(x+y)-2y/(x^2+y^2)-4y^3/(x^4+y^4)-8x^7/(x^8+y^8
先化简再求值:-3(2x-y)-{7-〔6x+2y-(10x-8y)〕+x-2(3x-4y)}已知x=-1/5,y=-5
已知:3x=8y.求(1)x+y/y (2)2x+3y/x-2y
(x+2)(x+3) (x-4)(x+1) (y+4)(y-2) (y-5)(y-3)
{3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1
根据下列条件分别求代数式4(x-y)+5 (x-y)-11(x-y)得值; 1、x=3,y=1;2
1) (x+y)^2-(x+y)^3 2) (x-y)^2-(x-y)^3 3)(x-y)^2-(y-x)^3 因式分解
不解方程组x+4y=6 x-3y=1求代数式7y(x-3y)的平方-2(3y-x)的立方
先化简再求值:(x-2y)²-(x+2y)(x-2y)-(x-3y)(x-y).其中x²+9y
y=5;x=14;y=((x=3*y,x+6),x-1); printf(''x=%d,y=%d'
去括号并合并同类项(1)3x-2(x+7)+2(2x+5) (2)(4x-3y)-[-(3y-x)+(x-y)]-5x