Answer:
(A) Let a represent the number of hours Cassie needs to work
(B) The inequality is 10 × a + 30 ≥ 140
(C) a ≥ 11
(D) Cassie needs to work babysitting for her neighbor for at least 11 hours to be able to buy the graphing calculator
Explanation:
The least amount Cassie needs for the graphing calculator = $140
The amount Cassey currently have saved = $30
The amount her neighbor offers for her to babysit = $10 per hour
(A) The definition of the variable is given as a = The number of hours Cassie needs to work
(B) The inequality that defines the situation is 10 × a + 30 ≥ 140
(C) Solving the inequality gives;
10 × a + 30 ≥ 140
10 × a ≥ 140 - 30
∴10 × a ≥ 110
a ≥ 110/10
∴ a ≥ 11
Which gives;
The number of hours Cassie needs to work = a ≥ 11 hours
(D) The solution means that Cassie needs to babysit for her neighbor for at least 11 hours to be able to buy the graphing calculator.