5x-7y=12,11x+19y=36

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 5x-7y=12,11x+19y=36 若(X×X+Y×Y)(X×X+Y×Y-5)=36,则X×X+Y×Y＝ 解一些方程组8(1/x+1/y)=16/x+x/y=19/(x+y)+6/(x-y)=312(x+y)=12(x-y)-11/(2x+y)-1/(x-2y)=53/(2x+y)-2/(x-2y)=5过程可以省略. [(y*y*y-y)/(xy+1)*(xy+1)-(x+y)*(x+y)]/[(x+y)*y/(x+1)]其中x=-11,y=1/12,化简再求值. 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 {x+y=5{3x-7y=11 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 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 大括号x+y/2+x-y/3=11/6 4(x+y)-5(x-y)=7 快 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 2(x-2y)²-7(x-2y)³+3(2y-x)²+(2y-x)³合并同类项 这个式子2（x-2y)²-7（x-2y)³+3(2y-x)²-(2y-x)³=2（x-2y)²-7（x-2y)³+3(x-2y)²+(x-2y)³=5(x-2y)²-6(x-2y)³=(x-2y)²(5-6x+12y) 已知x+y=-5,x*x+y*y=19求xy和（x-y)*(x-y)的值 3x+5y=30 7x-8y=11 x是多少 y是多少 （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