Question

8r^2 + 8 = 680
Solve by taking square roots

Answer 1

Answer:
`r=\Large\boxed{\pm 2√(21) }`

Explanation:

Given equation

`8r^2+8=680`

Subtract 8 on both sides

`8r^2+8-8=680-8`

`8r^2=672`

Divide 8 on both sides

`8r^2/8=672/ 8`

`r^2=84`

Take square roots on both sides

`r=\pm √(84)`

`r=\Large\boxed{\pm 2√(21) }`

Hope this helps!! :)

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