1.2y^2+8y+7=0
2y''+y'-y=0
2y+8y-1=0
1.5y+8y-6y=2y-3
{2x+y/3-2y=0 2(2x+y)-5=7y
y-7-8y=2y-3-5y 咋写?
微分方程(1)(y'')^2+5y'-y+x=0;(2)y''+5y'+4y^2-8x=0;(3)(3x+2y)dx+(
先化简,在求值:6y-(y+2分之y + 2-y分之y)除以y³-4y-2y²+8分之y,其中y=
y-3x=2,y-5x=4,y-7x=6,y-9x=8,y-11x=0方程组,
已知y^2+3y-1=0求y^4/y^8+3y^4+1的值
已知(3x+1)(3x-3)-3x+2)^2=-7,(y+7)(y-7)-y(y-7)=0,求8y^2-5y(-y+3x
求下列微分方程的通解或特解:(1) 3y''-2y'-8y=0 (2) 4y"-8y'+5y=0
已知实数x.y满足根号(x+y-8)+根号(8-x-y)=根号(3x-y-4)+根号(x-2y+7),求x,y