This is about variables. The problem is

Question

d/2.5 - 3.4 = 4.6. What are the steps in finding out what the d is?

Answer 1

first, collect the stuff with d on one side, and the plain numbers on the other. Recall that a true equation remains true if you do the same thing to both sides.

So, start by adding 3.4 to both sides:

d/2.5 - 3.4+3.4 = 4.6+3.4
d/2.5 = 8.0

Now, multiply both sides by 2.5:

d/2.5*2.5 = 8.0*2.5
d = 20