General solutions

Someone please show and explain me the solution to this.
How to find the general solutions for these differential equations?

1. y'-2y = 6

2.y'+y = 5sin.(4t/3 + pi) ....... (cospi= 3/5, sinpi= 4/5)

this are of form dy/dx+py=q

integrating factor=integral p dx
genaral solution is y(integrating factor)=integral(q integrating factor)dx+c

Have you tried Wolfram Alpha?
https://www.wolframalpha.com/input/?i=y'-2y+=+6
Click on the 'show steps' button on top right of the solutions column to see all steps.