5x+4y=144 (1)2x+y=40 (2)

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 化简[(3x+4y)^2-(2x+y)(2x-y)+(-x+y)(5x-y)]除以-2y,其中x=-1,y=1 x+y/3+x-y/2=6 4(x+y)-2(x-y)=40 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 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 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 (x-y)/(x+y)=3求( 3x-2y-1)/(x+y-5) {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/x-x+y/y-(x+y)(x-y)/y² y/x=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 若(x*x+y*y)(x*x+y*y)-4x*x*y*y=0,求代数式(x*x+5xy+y*y)/(x*x+2xy+y*y)的值 3x-2y=1 4x-5y (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 {(x+y)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? x+y+2(-x-y+1)=3(1-y-x)-4-(y+x-1),x+y=?