Question

What is the equation expression for three increased by d

Answer 1

Answer:

3+d

Not sure exactly what you're asking but three increased by d would give you 3+d.

Also to clear up any confusion,  equations are mathematical statements with two expressions set equal to one another. Expressions are sentence fragments that stands for a single numerical value.

Basically, expressions don't have equal signs and equations do. 3+d would be an expression.