Answer:
- 4, 7
Step-by-step explanation:
Let the required number be x.
Therefore, according to the given condition:
[tex] {x}^{2} - 28 = 3x \\ {x}^{2} - 3x - 28 = 0 \\ {x}^{2} - 7x + 4x - 28 = 0 \\ x(x - 7) + 4(x - 7) = 0 \\ (x - 7)(x + 4) = 0 \\ x - 7 = 0 \: or \: x + 4 = 0 \\ x = 7 \: or \: x = - 4 \\ [/tex]