Question

Find the product

(7+2u) (7-2u)

Options:

a) 49+4u

b) 49-4u(square root sign)

c) 4u(square root sign) - 49​

Answer 1

b)
`\boxed{\bold{(7+2u)(7-2u)=49-4u^2}}`

Explanation:

`(7+2u) (7-2u)=(7)(7)+(7)(-2u)+(2u)(7)+(2u)(-2u)=\\\\=49-14u+14u-4u^2=\ \underline{49-4u^2}`

Answer 2

b

Explanation:

if you mean squared and not square root, then it would be b because if you factor it back out, you will get the original expression back because of the subtraction of perfect squares.