sandy wrote:
The sum of x and y is at least 2 but no more than 5. If the total of twice x and three times y is non-negative and no more than 40, which of the following expresses all possible values of y?
A. −4 ≤ y ≤ 36
B. −10 ≤ y ≤ 30
C. −10 ≤ y ≤ 36
D. 0 ≤ y ≤ 40
E. 2 ≤ y ≤ 5
We can create the following inequalities:
2 ≤ x + y ≤ 5
0 ≤ 2x + 3y ≤ 40
Multiplying the first inequality by -2, we have:
-4 ≥ -2x - 2y ≥ -10
-10 ≤ -2x - 2y ≤ -4
Adding this to 0 ≤ 2x + 3y ≤ 40, we have:
-10 ≤ y ≤ 36
Answer: C