5x+8y-38=0(1) 3x-7y=11(2)
y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,
5x+8y-38=0(1) 3x-7y=11(2)
微分方程(1)(y'')^2+5y'-y+x=0;(2)y''+5y'+4y^2-8x=0;(3)(3x+2y)dx+(
若2x-3y+4=0则x(x*x-1)+x(5-x*x)-6y+7
先化简再求值(x-y)(x+y)-(x-2y) 的完全平方+x(3x-5y)-(x-y)(x-2y),其中x=1/2 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
3x+2=y 5x+4=y 7x+6=y 9x+8=y 11x=y 联立方程 有的话
(1){x+2y=0,3x+4y=6(2){5x+6y=16,7x-9y=5(3){9x-11y+1=0,4x-5y-3
x1:4x-3y=8;y=7-5x;2:2x-7y=8,3x-8y-10=0;3:4x-y=-1;4:5x-10y+15
3(x+y)-4(x-y)=11,2(x-y)+5(x+y)=27
5x-(1-11y)/8=5y-6x+2/9=3x+4y+7/6