x+y=84 5/8x+3/4y=58请解方程X,Y数值相同,用带入法解决

x+y=84 5/8x+3/4y=58请解方程X,Y数值相同,用带入法解决 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 请解答方程组：（39）2x+y=5 (40)x+y=7 (41)2x+3y=12 (42)2x+y=3ax+3y=7 2x-y=8 3x+4y=17 3x-5y=11(43)3x+y=82 (44)3(x-1)=y+5 45 x/4+y/3=7 (46)x+y/3 +x-y/2=610x-11y=87 5(y-1)=3(x+5) 2/3x+y/2=14 3(x+y-)2(x-y)=28 （5x+3y)(3y-5x)-(4x-y)(4y+x)= 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 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 {x+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 已知:3x-5y=0,求x/y,x-y/y,x-y/x 填空题 x+y/4=x-y/6=3x+12y+5/8 x= y= 3(2X+Y)+(2(2x-Y)=6 (8X+4y)-(10X-5Y)=2 (4x-2y-z)-{5x-[8y-2z-(x-2y)]-x-(3y-10z)}=? 已知3x=4Y,5Y=6Z,求 (1)x:y:z;（2）x+y/y+z.请说明道理， 解方程组8y+5x=84y-3x=7 方程组 因式分解 4x^3-4x^2y-(x-y) 方程组x-2y=8,3x-4y=5,x=?,y=? x+y=84 5/8x+3/4y=58