9:2=36:y

(y-2)(y^2-6y-9)-y(y^2-2y-15),其中y=1/2.先化简再求值. 9:2=36:y y- 2y+1/2=9- 8-y/4 y-2y+1/2=9-8-y/4 1.2y-0.04y=9y^2 1.2y-0.04=9y^2 |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. 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) 3(x+y)+2(x-y)=36 4(x+y)-5(x-y)=2 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=? 4(x-y)-3(x-y)=9 5(x-y)+2(x-y)=11 3(x+y)-2(x-y)=11 4(x+y)+3(x-y)=9 [T,Y]=ode45(@rigid,[0 1],[rand(15,1)]);plot(T,Y(:,1),'-',T,Y(:,2),'-.',T,Y(:,3),'.',T,Y(:,4),'-',T,Y(:,5),'-.',T,Y(:,6),'.',T,Y(:,7),'-',T,Y(:,8),'-.',T,Y(:,9),'.',T,Y(:,10),'-',T,Y(:,11),'-.',T,Y(:,12),'-.',T,Y(:,13),'.',T,Y(:,14),'-',T,Y(:,15),'.') (y-2)(y的2次幂-6y-9)-y(y的2次幂-2y-15),其中y=-2 化简求值：（y-2）（y²-6y-9）-y（y²-2y-15）其中y=1/2