Answer:
18
Step-by-step explanation:
Since Robyn bought 13 video games and got 31 at the end, if you take away 13 then you will get 18 meaning the answer is 18
Maths Sum:
There's 2 ways you could go this, there's the algebraic way of doing it (that I don't recommend for this type of question and is a bit to advanced right for this question also) which is:
x + 13 = 31
- 13 -13
x = 18
And there's the simple way of doing that I recmmend for this type of question which is:
31 - 13 = 18
