What is 3d+8=2d-7 is equations

3d + 8 = 2d - 7 equals d = -15.

First, subtract 2d from both sides. Your problem should look like: 3d + 8 - 2d = -7.
Second, simplify 3d + 8 - 2d to get d + 8. Your problem should look like: d + 8 = -7.
Third, subtract 8 from both sides. Your problem should look like: d = -7 - 8.
Fourth, simplify -7 - 8 to get -15. Your problem should look like: d = -15, which is your answer.

Hopefully this helps, I'm not exactly sure what you meant by "is equations," but this is how you solve the problem.