Question: When 5 is subtracted from the square of a number the difference will be 11. Find the numbers.

Solution:

Let the required number be represented by x.

According to the question,
When 5 is subtracted from the square of the number, the difference will be 11.

$or, x^2 - 5 = 11$
$or, x^2 = 11+5$
$or, x^2 = 16$
$or, x = \pm \sqrt{16}$
$\therefore x = \pm 4$

Therefore, the required numbers are 4 and (-4).

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