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Which value of c would NOT make 3x^2 + 5x + c factorable?

a) 2
b) -2
c) 22
d) -22

1 Answer

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Final answer:

The value of c that would not make the quadratic equation 3x^2 + 5x + c factorable is c = 22, because it results in a negative discriminant, indicating that the quadratic equation has complex solutions.

Step-by-step explanation:

To determine which value of c would not make the quadratic equation 3x^2 + 5x + c factorable, we can use the discriminant method from the quadratic formula. The discriminant is found by using b^2 - 4ac. A quadratic equation is factorable over the real numbers if and only if the discriminant is a perfect square (which means the quadratic formula will produce rational solutions).

In this case, a = 3 and b = 5.

The discriminant for the equation 3x^2 + 5x + c is 5^2 - 4(3)(c), which simplifies to 25 - 12c. To determine which provided values of c would result in a non-factorable quadratic, we need the discriminant to be a non-perfect square or a negative number (indicating complex solutions).

  1. For c = 2, the discriminant is 25 - 12(2) = 1, which is a perfect square.
  2. For c = -2, the discriminant is 25 - 12(-2) = 49, which is also a perfect square.
  3. For c = 22, the discriminant is 25 - 12(22) = -239, which is negative, thus non-factorable over real numbers.
  4. For c = -22, the discriminant is 25 - 12(-22) = 289, which is a perfect square.

Therefore, c = 22 is the value that would not make the quadratic equation factorable.

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