1.2y-0.04=9y^2

1.2y-0.04y=9y^2 1.2y-0.04=9y^2 (y-2)(y^2-6y-9)-y(y^2-2y-15),其中y=1/2.先化简再求值. y- 2y+1/2=9- 8-y/4 y-2y+1/2=9-8-y/4 |2y-6|=9+4y 先化简,再求值：(y-2)(2y²-3y+9)-y(y²-2y+15),其中Y²－4Y-4=0. y (3y^2+8y-3)-6y(3y+2y-1)+9y x-y/x-x+y/y-(x+y)(x-y)/y² y/x=2 yy''-(y')^2=y^2y' yy''-(y')^2=y^2y' y+y'-2y=2x 微分方程y - 2y' + y = x 2y''+y'-y=0 常微分方程的通解dy/dx=(x-y+1)/(x+y-3)y^4=2y^n+y=0y''+6y'+9y=e^(-3x)y''+y'-2y=4e^(2x) 9y^3-9y^2+2y+1=0 求3y-1=? 先化简,再求值;y^2/y-2+4/2-y,其中y=-9/2 x+(9-8-y)=10 y+y-(9-8-y)=2 x-y=xx-9.9x xy=11y-1 y=? x=? x+y-xy=?x+(9-8-y)=10y+y-(9-8-y)=2x-y=xx-9.9xxy=11y-1 y=?x=?x+y-xy=?