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Which value of c would NOT make 3x2+5x+c factorable?

User Incanus
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2 Answers

6 votes

Final answer:

A value of c that makes the discriminant of the quadratic 3x^2 + 5x + c non-perfect square results in the expression being non-factorable. For example, c=3 would result in a discriminant of -11, which is not a perfect square, therefore the quadratic would be non-factorable.

Step-by-step explanation:

The question is asking us to find a value of c that would result in the quadratic expression 3x^2 + 5x + c being non-factorable. To determine this, we use the discriminant in the quadratic formula, which is b^2 - 4ac. For a quadratic to be factorable over the integers, the discriminant needs to be a perfect square.

In this case, our equation is 5^2 - 4 × 3 × c. The quadratic will be non-factorable if the discriminant is not a perfect square. Thus, we must find a value of c such that 25 - 12c is not a perfect square.

For example, if c=2, then 25 - 12 × 2 gives us 1, which is a perfect square, meaning the quadratic is factorable. However, if c=3, the discriminant would be 25 - 12 × 3 = -11, which is not a perfect square, and thus the quadratic would be non-factorable.

User Zoccadoum
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7.2k points
2 votes
If c = 2 it is factorable. If c =-2 it is also factorable. If c= -8 it would factor as well. If your answer choices are any others, I do not think they would make it factorable. Hope this helps.
User Xnnyygn
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6.4k points
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