Problem 21

Question

Factor each trinomial, or state that the trinomial is prime. $$x^{2}-8 x+15$$

Step-by-Step Solution

Verified
Answer
The factored form of the trinomial \(x^{2}-8 x+15\) is \((x-5)(x-3)\).
1Step 1: Identifying factor pairs of the constant term
Firstly, identify the pairs of factors of the constant term, which is 15 in this case. The pairs are (1,15) and (3,5). Both the pairs multiply to give 15.
2Step 2: Identifying the correct factor pair
Next, find the pair of factors that can add or subtract to give the coefficient of the second term, which is -8. Here, you see that (3,5) can subtract to give -8 if 5 is considered negative but not the pair (1,15). So, (3,-5) is the correct pair.
3Step 3: Factoring the trinomial
Now, replace the middle term (which is -8x) with -3x and -5x and factor by grouping, which would give \((x-5)(x-3)\).