Given that x = 7, write an equation that contains two different equivalent expressions each including at least one variable (x) and the operations: addition, subtraction, multiplication, and division.

Well here are two equivalent different expressions of my making that you could use for this question.

f(x) = 2x - 7
g(x) = 3x - 28 / 2

When x = 7, these two different expressions will equate to the same value of 7. If you meant something else let me know, otherwise this is what you should put for your essay-question.