Use FOIL for this scenario

Question

5y+7x)(5y-7x

Answer 1

(5y+7x)(5y-7x)

First terms: (5y)(5y) = 25y²

Outer terms: (5y)(-7x) = -35xy

Inner terms: (7x)(5y) = 35xy

Last terms: (7x)(-7x) = -49x²

Here is what he have now: 25y² - 35xy + 35xy - 49x² Combining like terms, the 2 middle terms cancel giving:

25y² - 49x²

Answer 2

Problem: (5y + 7x)(5y - 7x)

Steps:

1. Multiply first term to the second group
2. (5y * 5y) (5y * -7x) = 25y² - 35xy
3. Multiply second term to the second group
4. (7x * 5y) ( 7x * -7x) = 35xy - 49x²
5. Write out the new terms
6. 25y² - 35xy + 35xy - 49x²
7. Combine like terms
8. -35xy + 35xy = 0xy
9. 25y² - 49x²

Solution: 25y² - 49x²