Question

One of the solutions to x2 − 2x − 15 = 0 is x = −3. What is the other solution?

x = −5
x = −1
x = 1
x = 5

Answer 1

Answer: x = 5

Explanation:

x² - 2x - 15 = 0

x² + 3x - 5x - 15 = 0

x(x + 3) - 5(x + 3) = 0

Therefore, x + 3 = 0

x = 0 - 3 = -3

Also, x - 5 = 0

x = 0 + 5 = 5

Therefore, the solutions to x² - 2x - 15 = 0 is x = -3 and x = 5. Therefore, the correct option is D.