·0.4y+0.9/0.5-y-5/2=0.3+0.2y/0.3求y
初一数学解方程:(0.4y+0.9/0.5)-(y-5/2)=0.3+0.2y/0.3
y·y''=1+y'^2求通解
求微分方程y”-3y’+2y=5
求y''-2y'+5y=(e^x)sin2x
已知x-y/x+y=3,求代数式5(x-y)/x+y-x+y/2(x-y)
给位懂matlab的朋友们急求z=0.8-(0.3x^2+x+y^2+y-0.05)*(0.5+y)/(0.55+y+y
求y'=y/(y-x)
已知x+4y-2x+8y+5=0,求x^4-y^4/2x+xy-y·2x-y/xy-y÷(x+y/y)的值.
4分之x-y=﹣1 x+4y=4,求x,y 0.2x+0.5y=5分之1 0.4x+0.1y=5分之2,求x,y
已知:4x = 5y,求(x+y) :y
求y’’-2y’+2y=0
求微分方程y"-2y'+y=0的通解.