Math Chapter 1.2

Question 1

Evaluate 4y - 15 for y = 9.

Answer 1

Answer: 21
Explanation: Substitute y = 9 into the expression: 4(9) - 15. Multiply first to get 36 - 15, then subtract to get 21.

Question 2

Evaluate 63 - 5x for x = 7.

Answer 2

Answer: 28
Explanation: Substitute x = 7 into the expression: 63 - 5(7). Multiply first to get 63 - 35, then subtract to get 28.

Question 3

Evaluate 4(t + 3) + 1 for t = 8.

Answer 3

Answer: 37
Explanation: Substitute t = 8 into the expression: 4(8 + 3) + 1. Simplify the parentheses to get 4(11), then multiply to get 44. Add 1 to get 37.

Question 4

An online music store charges $14 per CD and $6 for shipping. Write and evaluate the cost of ordering 4 CDs.

Answer 4

Answer: $62
Explanation: The cost is given by the expression 14n + 6, where n is the number of CDs. For n = 4, substitute to get 14(4) + 6. Multiply to get 56 + 6, then add to get $62.

Question 5

A store orders b bottles of energy drinks. Write a variable expression for the number of cases if each case contains 24 bottles. Evaluate the expression for b = 120.

Answer 5

Answer: 5 cases
Explanation: The number of cases is given by b / 24. Substitute b = 120 to get 120 / 24 = 5 cases.

Question 6

Evaluate 3ab + c for a = 2, b = 5, and c = 10.

Answer 6

Answer: 35
Explanation: Substitute a = 2, b = 5, and c = 10 into the expression: 3(2)(5) + 10. Multiply to get 30 + 10, then add to get 40.

Question 7

Evaluate 6(g + h) for g = 8 and h = 7.

Answer 7

Answer: 90
Explanation: Substitute g = 8 and h = 7 into the expression: 6(8 + 7). Simplify the parentheses to get 6(15), then multiply to get 90.