Question

8d + 3d – 3d – 8 = 3d

Answer 1

Hello,
8d+3d-3d-8=3d;
8d-8=3d;
8d-3d = 8;
5d = 8;
d = 8/5

bye :-)

Answer 2

Let's start with deleting +3d and -3d (because they have opposite signs)

8d-8 = 3d

Move unknown term (3d) to the left of equal with changed sign and known term (-8) to the right of equal with chenged sign.

8d-3d = 8

5d = 8

Divide both for 5

5d/5 = 8/5

d = 8/5