4X 3Y=86 X Y=24 X是14 Y是10是怎样求出的

4X 3Y=86 X Y=24 X是14 Y是10是怎样求出的 (x-y) (x-2y)+(x+2y) (x-3y)-2(x-3y) (x-4y)= 若x+y=4,则多项式1/2(x+y)+4(x-y)-3（x-y）-3/2(x+y)-x+y值是（） 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y 若(-x+6):(x-y):(4x+y)=3:14:1,求x+y (-x+6):(x-y);(4x+y)=3;14:1,求x+y的值. 已知实数x,y满足（x+y)(x+y+3)-4=0则x+y的值是 x、y是自然数,规定x@y=4x-3y,那么5@6=? 例X=1 y=21.X+Y=5 X-Y=15 2.2X+3Y=4 5X+6Y=7 3.X+3Y=5 3X+Y=-1 4.2X+Y=3 3X+5Y=11 5.4X+3Y=6 2X+Y=4 6.X+Y=180 X=3Y-10 7.3X-2Y=3 2X-Y=7 8.5X+3Y=7Y X+Y=45 9.3X+4Y=126X+8Y=24 X:6Y=1:4 10.X+Y=138 X-45=Y+53 11.X+Y=60 14Y=20X 12.2X+3Y=15.5 5X+6Y=35 13.X+Y=170 3 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 {3(x+y)+3(y+x)=1,3(x+y)+4(y-x)=-1 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 （3x-y)(y+3x)-(4x-3y)（4x+3y)=? {3(x+y)-4(x-y)=4 {x+y/2 + x-y/6=1 x+y/2+x-y/3=6,4(x+y)-3(x-y)=-20 {(x+y)/2+(x-y)/3=6 4(x+y)-3(x-y)=-20 4(x+y)-3(x-y)=-20,2/x+y+3/x-y=6 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9