13x+14y=41 14x+13y=40

x/2+y/7=13/14,x+y=? x/2+y/7=13/14,x+y=? 把x^4+2x^2y^2+y^4-2x^3y-2xy^3分解因式x=14、y=13时的值 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x^2+y^2+13-4x+6y=0,求(2x-y)^2-2(2x-y)(x+2y)+(x+2y)^2 导数的计算练习题导数的计算（1）y=x^5 （2)y=sinx(3)y=1/x^3(4)y=5^√x(5)y=cosx(6)y=5^x(7)y=log3^x(8)y=lnx(9)f(x)=x^3-x^2-x+1(10)y=2x^3-3x^2+4x-1(11)y=x inx（12）y=xsinx-cosx(13)y=cosx/x(14)y=3x(x^2+2)(15)f(x)=(x-1)^2+3(x-1)(16)f(x)=1 x+x+x+y=20 x+x+y=14 x=?y=? x+x+x+x+y=40 x+y= 13x=y= 13x+14y=41 14x+13y=40 {13x+14y=41① {14x+13y=40② {5x+2y=13,3x-2y=-3,{2x+3y=5,4x-2y=1,{x+y=11,y+z=14,x+z=15,{x+y+z=6,x+z=16,x-y+2z=17解方程, {5x+2y=13,3x-2y=-3,{2x+3y=5,4x-2y=1,{x+y=11,y+z=14,x+z=15,{x+y+z=6,x+z=16,x-y+2z=17解方程, 5x+14=y,7x+4=y x+4y=14 x+5y=15 6(x-y)-2(x+y)=14 3(x-y)+(x+y)=5 X+Y=290 4%x+5%y=13