Question

The sum of a whole number and twice the square of the number is 10. Find the number

Answer 1

2 + (2)^2 × 2 = 10

That's your answer 2

Answer 2

Let the number be x

A/Q,
$x + 2 {x}^{2} = 10 \\ = > 2 {x}^{2} + x - 10 = 0 \\ = > 2 {x}^{2} + (5 - 4)x - 10 = 0\\ = > 2 {x}^{2} + 5x - 4x - 10 = 0 \\ = > x(2x + 5) - 2(2x + 5) = 0 \\ = > (2x + 5)(x - 2) = 0$
Therefore,
$2x + 5 = 0 \\ = > 2x = - 5 \\ = > x = \frac{ - 5}{2} \: (rejected) \\ and \\ x - 2 = 0 \\ = > x = 2$
Hence, the whole number is 2.

Hope it'll help...