Question

How do you foil `(7x + 7)(5x – 4)`?

Answer 1

`=color(blue)(35x^2+7x-28`

Explanation:

The expression is :`(7x+7)(5x-4)`

F O I L involves carrying out the below operations in the following order:

1) product of First terms :`(color(blue)(7x and 5x))`+

2)product of Outside terms:`(color(blue)(7x and -4))`+

3)product of Inside terms:`(color(blue)(7 and 5x))`+

4)product of Last terms:`(color(blue)(7 and -4))`

1) `7x*5x=color(blue)(35x^2) +`

2) `7x * -4=color(blue)(-28x)+`

3) `7 * 5x = color(blue)(35x)+`

4) `7 *-4 = color(blue)(-28`

adding all the terms

`=color(blue)(35x^2-28x+35x-28`
`=color(blue)(35x^2+7x-28`