Differential Equations Problem

[Eddie W. Shore]

I received an email with the question:
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I am trying to solve the simplest first order ode I could think of:

dy/dx - 4y = 0 for y(0) = 1

the solution should be y(x) = y(0) e^4x

I tried

plotode(4*y, [y], [1])

but I just get the error message "bad argument type".

I thought perhaps I need to give it the independent variable, so I tried

plotode(4*y, [x,y], [0,10)

which now runs, but it makes a vertical line straight up.
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I have tried to use both odesolve and desolve with no success.

odesolve(4*y, [x,y]) returns the same
odesolve(4*y, [x,y], [0,1]) returns Bad Argument Type
desolve(4*y, [x,y], [0,1]) returns [[ ]]
desolve(y' - 4*y = 0, [x,y], [0,1]) returns [[ ]]

Any help?