Respuesta :
Let the certain number is x.
According to question,
x + 5 = 2x + 12
Or, 2x - x = 5 - 12
Therefore, x = -7
Hence, the required certain number is -7.
According to question,
x + 5 = 2x + 12
Or, 2x - x = 5 - 12
Therefore, x = -7
Hence, the required certain number is -7.