Question

Identify the number that, when subtracted by its square

Q: Answer-Identify the number that, when subtracted by its square root, results in a difference of 42.

Let the number be x. So, x - 42 x On, squaring both sides, we have x - 42 2 x 2 Or, x2 1764 - 84x x Or, x2 - 85x 1764 0 Or, x2 - 36x - 49x 1764 0 Or, xx - 36 - 49x - 36 0 Or, x - 49 x - 36 0 So, x 49 or x 36 We can see that x 36 will not satisfy the equation, so x 49 Hence, option d.