Question

How do you solve `v^2+ 10v - 21 = 0` by completing the square?

Answer 1

`y = v^2 + 10.v - 21 = 0`

`y = v^2 + 10v + 25 - 25 - 21 = 0`

(v + 5)^2 = 46

`v + 5 = sqr46 -> v = -5 + sqr46`
`v + 5 = -sqr46 -> v = -5 - sqr46`