Which expression means the sum of 5 and a number? a. g × 5 b. g – 5 c. g + 5 d. g ÷ 5

For this case, the first thing you should do is define a variable.
 We have then:
 g: unknown number.
 We now write the expression in algebraic form.
 the sum of 5 and a number:
 g + 5
 
 An expression that means the sum of 5 and a number is:
 C. g + 5