Write and evaluate the expression. Then, check all that apply. eight increased by a number; evaluate when n = 5.3 First, write an expression. The correct expression is n + 8. The correct expression is 8n. Second, substitute 5.3 for the variable, n. Third, simplify by adding 5.3 and 8. Third, simplify by multiplying 5.3 and 8. The answer is 42.4. The answer is 13.3.