x+4y=14 x+5y=15

x+4y=14 x+5y=15 5x-4y(y-x)=? 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 x+y／y=5／4,则x／y=---------------- 5x+14=y,7x+4=y 2（x+y)-3(x-y)=3 ,4(x+y)+3(x-y)=15 已知：4x = 5y,求(x+y) ：y x*x+2x+y*y-4y+5=0 x= y= （5x+3y)(3y-5x)-(4x-y)(4y+x)= 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 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 先化简再求值(x-y)(x-2y)+(x-2y)(x-3y)-2(x-3y)(x-4y) x=4 y=5 x+2y=3（x+y）+5 3x-4y=4（x+y）-15 解方程x+y+(x+y/2)=15 3x+5y+4(x+y/2)=62 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 4x-2*(10-x)-10=5y-3*(10-y)x+y=14