Did I answer this correctly?

Part 2: Using complete sentences, explain how you know that the equation from Part 1 cannot be solved by factoring, but can be solved by using the quadratic formula.

When the coefficients form the first and third terms are multiplied you get -15, there are not two numbers that multiply to -15 and add to -1 (the coefficient of the second term). This shows that it cannot be factored and the quadratic formula must be used.

Question

Did I answer this correctly? 

Part 2: Using complete sentences, explain how you know that the equation from Part 1 cannot be solved by factoring, but can be solved by using the quadratic formula.

When the coefficients form the first and third terms are multiplied you get -15, there are not two numbers that multiply to -15 and add to -1 (the coefficient of the second term). This shows that it cannot be factored and the quadratic formula must be used.