Answer: The number is - 22
Explanation:
Let the negative real number be x.
The square of the sum of the number and 2 is (x + 2)^2.
given that the square of the sum of the number and 2 is equal to 400, it means that
(x + 2)^2 = 400
Taking the square root of both sides,
x + 2 = √400
x + 2 = ± 20
x + 2 = 20 or x + 2 = - 20
x = 20 - 2 or x = - 20 - 2
x = 18 or x = - 22
Since the number is negative, it is - 22
