y''-3y'-10y=0, y=1, y'=10 at x=0

I know how to get it to the general equation correctly, but where do I go from there in these types of questions?

The general form is y=C1e^-2x+C2e^5x

Do I plug in x=0? That would leave C1+C2=10 which doesn't seem right....

I need to get to y(x)=__________