x/3+y/4＝54/60 x/5+y/4＝42/60 求x的多少y的多少

因式分解(x-2y)(x-3y)+(x-4y)(x-5y)+（x-3y)(x-5y)+(x-2y)(x-4y) ｛x/60+y/80=10,x/60+y/40=15、｛2x/3+3y/4=1/5,5x/6-5y/2=2、｛5/2(x+y）=1200,10/3（x+y）=1200｛4x+5y=98,5y-4x=2、｛x/3+y/4=54/60,y/4+x/5=42/60怎么解?{40-y=x-4 40-y=y-x 初中数学题(-x-y+5)-(4x+3y-1)-(-4x-5y) 其中x-y＝-10 初二上学期方程题 4x+y=5 5x+4y=63x-2y=1 2x+3y=13x-2y=7 7x+5y=32x+3y=17 2x-y=-4x+5y=6 2x+y=23x-6y=4 3x+2y=52x+y=73x-4y=53x+y=1x-2y=-1x+y=42x+3y=92x-3y=74x+5y=3x+y=20004x+6y=90003x+5y=113x-2y=42x+3y=215x-2y=5x+y=54x+3y=182x+3y=16x+4y=132x+3y=40x （5x-3y)(3y+5x)-(4y-3x)(3x-4y) 5/4(x+y)(-x-y)^3*[-4/3(x-y)]*[-3/5(y-x)^2] （5x+3y)(3y-5x)-(4x-y)(4y+x)= (3x-4y)(5x-4y)-(7x-8y)(6y-5x) 5x^3y(x-y)^3-10x^4y^3(y-x)^2因式分解 5x^3y(x-y)^3-10x^4y^3(y-x)^2 5X^3Y(X-Y)-10X^4Y^3(Y-X)^2因式分解 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 （x+y）^6/(x+y)^4-(x-y)^5/(x-y)^3 化简 .. (2x-y)(3x-4y)-2(x-y)(2x-5y)简便运算 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 （x-y）^3×（y-x）^4+（x-y）^2×（y-x）^5 计算(x^8-x^7y+x^5y^3-x^4y^4+x^3y^5-x^y^7+y^8)(x^2+xy+y^2)