8x+5y=13,4x-9y=-2

4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 (4x-2y-z)-{5x[8y-2y-(x+y)]-x+(3y-10z)]=? kuaihuajian 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y 联立方程 有的话 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y 3x+2=y 5X+4=Y 7X+6=Y 9X+8=y 11x=y要如何计算 3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y怎么解 y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,无 9y=3x-(x-1),4(x+y)-(2x+4)=8y 3x-2y=9 x-3y=2 x+y=5 x+2y=3 y=x 2x+y=8 已知X.x+y.y-4x+2y+5=0,求4X.X-12X Y+9Y.y的值 解这些方程组 (1) 7x-2y=96 5x-3y=45 (2) 4x+2y=50 2x+3y=47 (3) 4x+2y=66 7x-3y=70(4) 11x+9y=49 13x-3y=17 (5) 2y-x=1 13x-8y=59 (6) 18x+29y=307 16x+28y=284 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 x*x+2x+y*y-4y+5=0 x= y= 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27 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+y=1 ,xy=-6{x(2x-3)=0,y=x²-1{(3x+4y-3)(3x+4y+3)=0,3x+2y=5{(x-y+2)(x+y)=0,x²+y²=8{(x+y)((x+y-1)=0,(x-y)(x-y-1)=0 x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2