The square of a positive number is 56 more than the number itself. Find the number.

Question

I am not sure how to solve. Which method should I use?

Answer 1

x² = x + 56

is what the problem is asking you.

 

You can arrange it to be

 

x2 - x - 56 = 0

 

Solve the quadratic equation and you will get two roots.  Your answer will be the positive number!