Question

7.5 - factoring polynomials - part 1
factor this quadratic expression.
$x^2 + 3x - 28$

Explanation:

Step1: Find pair of factors of -28

We need two numbers that multiply to $-28$ and add to $3$. The numbers are $7$ and $-4$, since $7 \times (-4) = -28$ and $7 + (-4) = 3$.

Step2: Write factored form

Use the two numbers to split the quadratic into binomial factors.
$x^2 + 3x - 28 = (x + 7)(x - 4)$

Answer:

$(x + 7)(x - 4)$