Answer: x = -3
Step-by-step explanation:
Let the number be x , that is the square of x is [tex]x^{2}[/tex].
From the first statement :
[tex]x^{2}[/tex] - 18 = 3x
writing the equation in a standard quadratic format , we have
[tex]x^{2}[/tex] - 3x - 18 = 0
Factorizing , we have
(x - 6 )(x + 3 ) = 0
x - 6 = 0 or x + 3 = 0
Therefore :
x = 6 or x = -3
Therefore , the negative solution implies x = -3
