5x-2y=1 x=7-3x

若2x-3y+4=0则x（x*x-1)+x(5-x*x)-6y+7 用递归法求y=x-(x*x*x/3!)+(x*x*x*x*x/5!)-(x*x*x*x*x*x*x/7!)+. x+y=1 5x-2y=8 3x-y=7 2x-y=3x表示y和用y表示x {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)/2+(x-y)/3=1,(x+y)-5(x-y)=2.求x=?,y=? x-y/7 - x+y/10 =1/2 2(x-y)-5(x+y)=3修改、、、、（x-y)/7-(x+y)/10=1/2 2(x-y)-5(x+y)=3 若(5x+y)(7x+10y)=1/2,则x/y=______;若x+1/x=3,则x^2+1/x^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 7x-3y/5=5x-y/3-x+y/2 x-1/5=y+1/3 3x-y+x=3 4【X-y-1】=3【1-y】-1 5x-4y+4x=3 2x+y-3x=11 【 x除以2 】-【y 除以3】 =2 2x+7y-3x=19 x+y+x=12 3x+2y-x=18 { x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3 { x-y/7-x+y/10=1/2 {2(x-y)+5(x+y)=3 已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y) 3x+5y-(x+y)=6 2(x+y)-3x=-7 （2x+y-1)(2x-y+1)-(3x+y)(3x-y),其中x=5分之1, (x-2)(x+2)-(x-2)(x+2)-(x-1)(x+3)-(x+2)还有（2x+3y-2)(2x-3y+2)还有已知xy²=-2 求xy（2x³y^7-5x²y^5-y） 坐等我搞错了(x-2)(x+2)-(x-1)(x+3)-(x+2)² 函数,y=3x/(x^2+x+1) ,x