Hi!
Our goal is to isolate d on one side. Whatever we do to the equation, we do to both sides.
Add d to both sides.
4-d+d<4+d+d
4<4+2d
Subtract 4 from both sides
4-4<4-4+2d
0<2d
Divide by 2 on both sides
0/2<2d/2
0d>0
The answer is d>0
Hope this helps! :)
-Peredhel
