Final answer:
The expression '20n + 20n' can be simplified to '40n' by combining like terms.
Step-by-step explanation:
The provided expression 20 n=3 + 20n=3 seems to be incorrectly transcribed or may contain typos, as it does not represent a typical mathematical expression. It's possible that the 'n=3' within the expression was intended to communicate a multiplication sign, which should be indicated as '20 * n' or '20n'. Assuming the expression should read 20n + 20n, it can be simplified by combining like terms. Since both terms are just the variable 'n' multiplied by 20, we can add them together to get 40n, which is the equivalent expression when simplified.