Question

Rachel's goal is to sell at least $200 worth of her band's CD. If each CD sells for $10, and she has already sold 13 CDs, which of the following inequalities could be used to determine x, where x is the number of additional CDs Rachel needs to sell to achieve her goal?

Select one:
A. 10(13) − x ≤ 200
B. 10(13) + x ≥ 200
C. 10(13) − x ≥ 200
D. 10(13 + x) ≤ 200
E. 10(13 + x) ≥ 200

Answer 1

Answer:

E. 10(13+x)$\geq$200

Step-by-step explanation:

Rachel want to sell at LEAST $200. This means that all less than or equal to inequalities can be disregarded, leaving B, C and E.

Next, solve for x in each equation.

B, x $\geq$ 70

C, x $\geq$ -70

E, x $\geq$ 7

Now C can be disregarded as she cannot sell -70 CD's, leaving B and C.

Now write a new equality that solves the problem.

10(13)+10(x)=200

13 being the number she has already sold and x being the number she still has to sell to make up the difference.

sub in the answer for B:

10(13)+10(70)=200

130+700$\neq$200

∴ x $\neq$ 70

sub in the answer for E:

10(13)+10(7)=200

130+70=200

200=200

∴ x=7.

∴ Inequality E is the correct answer.