5x-7y=23,7x+4y=46

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 7x:4y,x:y=( ):( 解方程组(x+y)(x-2y)=-5 (x-y)(x+2y)=7 {6(x-y)-7(x+y)=21 {2(x-y)-5(x+y)=-1 把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)= 3(x-y)把(x-y)看作一个整体,化解:5(x-y)+2(x-y)-4(x-y)=3(x-y)²-4(x-y)+7(x-y)-6(x-y)²= 5x+14=y,7x+4=y 把(x-y)看做一个整体,合并同类项5(x-y)+2(x-y)-4(x-y)=3(x-y)次方-4(x-y)+7(x-y)-6(x-y)次方= 5X+16X= Y+9Y= X+7X-4X= (x-y)(x-2y)+(x-2y)(x-7y),其中X=4,Y=1.5 计算3x/(x-3y)+(x+y)/(4y-x)-7y/(x-4y)=? 解方程组 x+y/5+x-y/2=7 4(x+y)-5(x-y)=2 方程2分之x+y+2分之x-y=7,4(x+y)-5(x-y)=2 解方程组x+y/2+x-y/2=7,4(x+y)-5(x-y)=2... 大括号x+y/2+x-y/3=11/6 4(x+y)-5(x-y)=7 快 1.{3x+2y=73x-4y+12 {x-6y=-23x+4y=53 {8x+3y+2=06x+5y+7=04 {2x-y=650%x+12.5%y=25%×35 {|x |+y=2|x |+2y=3希望可以有过程,用加减消元法谢谢了 X/Y=2/5 X+60/Y=4/7 问X.Y各是多少 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 已知|5x-y-8|+(7y-x+2)=0则4x+6y