Answer: Yes, 5 is a substitute for x.
Explanation:
Yes, 5 is a substitute for x because, 4x or, 4x5 is 20. Knowing the PEMDAS method, that is what we would use. So since multiplication is first, we use the 4x first.
The other side: 8x or, 8x5, is 40. 40-13=27. So yes, 5 is a substitute for x.