Need help solving some 2nd order DEs

Hi to everyone. I need help. I have few equations that i can not solve. If there is anyone that can help...please solve them step by step. I need them as fast as posible.....(Headbang)

1. y"+y'=e^x+2*cosx

2. x^2*y"-2*x*y'+2*y=2*x^3-x

3. y"+y'-2*y=(x^2-1)e^(2*x)

4. y"'-4y'=x*e^(2*x)+sinx

5. What kind of differential equation will we have if we put x=1/t in x^4*y"+2*x^3*y'-4*y=1/x (the new differential equation should be solved using Laplas transforamtion)

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Thanks