1/2x + 4/5x =2
here is a slightly different way.
I would have multiplied both sides by 10
10(1/2x + 4/5x) =10*2
5x+8x=20
13x=20
x=20/13
(1/2)x + (4/5)x =2 simplify
5/10x + 8/10x = 2
13/10x = 2 multiply both sides by 10/13
x = 20/13