FOIL is an 'acronym'. It helps you remember how to multiply
two binomials ... like (2x-7) and (5x+5) .
FOIL stands for "First, Outside, Inside, Last". Here's how it's used
to multiply these particular two binomials:
(2x - 7) (5x + 5)
First: (2x) (5x) = 10x²
Outside: (2x) (5) = 10x
Inside: (-7) (5x) = -35x
Last: (-7) (5) = -35
Add them all together, and you have the product:
10x² + 10x -35x -35
Simplify the sum: 10x² - 25x -35
or 5(x² - 5x - 7) .