Yes, "30 plus" should be hyphenated when used as a compound adjective before a noun, as in "30-plus participants." However, when used in other contexts, such as "participants aged 30 plus," it does not require hyphenation. Always consider the placement in the sentence to determine if hyphenation is necessary.
Yes, it should be hyphenated.
Yes it should be hyphenated.
Yes it should be hyphenated.
yes check-up should be hyphenated
It should be hyphenated.
"Field" is not hyphenated.
Yes it should be hyphenated.
Yes it should be hyphenated.
Yes it should be hyphenated.
No it shouldn't be hyphenated.
Self-made should be hyphenated.
Yes, "low-to-intermediate" should be hyphenated when used as a compound modifier before a noun.