Factor x2 – 3x – 28.

An x-method chart shows the product a c at the top of x and b at the bottom of x. Above the chart is the expression a x squared + b x + c.
Identify the values that should be written to complete the X diagram.
On the top:

On the bottom:

On the sides:
Rewrite the expression using the numbers on the sides of the X diagram.
Use double grouping to factor the four terms.
x2 – 3x – 28 =