I am reviewing Algebra for my GRE test. Here is one inequality problem that I do not understand...

I will provide the equation, the choices of answers, and their answer. I want to know HOW they solved it! Thank you!

Equation:

the letter x represents variable "x"

Equation writing in words: If 3x PLUS 4 is GREATER THAN Seventeen, 3x PLUS 7 is GREATER THAN

If 3x + 4 > 17, 3x + 7 >

Choices for Answers:

A.

13

-----

3

B.

22

-------

3

C. 14

D. 17

E. 20

Their answer:

3x + 7 = (3x + 4) + 3 > 17 + 3 = 20

I appreciate any feedback for this type of inequality problem!

Thank You