3x+5=4x+1,还有9-3Y=5y+5

3x+5=4x+1,还有9-3Y=5y+5 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 X+2y=o 3X+4y=6 方程组 要过程还有5X+6y=16 7X-9Y=5 X+2y=o 3X+4y=6 方程组 要过程还有5X+6y=16 7X-9Y=5 (x-y)/4+(x+y)/5=1/4 (x+y)/9-(x-y)/3=//2(x-y)/4+(x+y)/5=1/4(x+y)/9-(x-y)/3=//2 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 y=1+4x+x^2/1+x^2值域还有y=x^2-2x+3/x^2-x+1值域 y=x^2-4x+5/2x-4(x≥4)值域 （x+y-5)*（x+y-5)+（x-y+3)=0 x*x-y*y 已知:3x-5y=0,求x/y,x-y/y,x-y/x （5x+3y)(3y-5x)-(4x-y)(4y+x)= 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)/(x+y)=3求( 3x-2y-1)/(x+y-5) 二元一次方程,2x-3y=-1 4x-y=52x-3y=-1 4x-y=52x+y=4x+2y=53(x-1)=4(y-4)5(y-1)=3(x+5)下面这个用两种方法解,一种是换元法,还有一种是整理公式的方法,x+y/3+x-y/2=63(x+y)-2(x-y)=28 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 {5(x-3y)-6=2x+1 3(x+6y)+4=9y+19 ｛3分之2（x-y）=4分之x+y-1 6）x+y)=4(2x-y)+16 {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? {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