The square of a certain negative number is equal to 5 more than one half of the number what is the number

The square of a certain negative number is equal to 5 more than one half of that number

what is that number

let x be that number

thus x² = x/2 + 5

x² - x/2 - 5 = 0

2x² - x - 10 = 0

(2x-5) (x + 2) = 0

x = 5/2 or - 2

so the number is - 2