Question

How do you solve `x^ { 2} - 20x + 100= 28`?

Answer 1

`S = {10 +- 2sqrt7}`

Explanation:

`x^2 - 20x + 100 = 28`
Factorize
`<=> (x-10)^2 = 28`
`<=> x-10 = sqrt28` or `x-10 = -sqrt28`
`<=> x=10+2sqrt7` or `x=10-2sqrt7`