Question

What is 29+d=54;24,25,26, how do I solve it?

Answer 1

First, set up your equation (we'll start with the first number you listed)
29+d=54
Next, subtract 29 from both sides
d=25
Now do the same for each number; I will demonstrate anyways.
29+d=24
d=-5
29+d=25
d=-4
29+d=26
d=-3

Answer 2

d=25 because you would subtract 29 on both sides of the = so you can get your variable, d, alone. So, 54 minus(-) 29 equals 25.