The sum of a number and its square is 56. Find the number.

Question

They have not gave me any other details about the problem. I have no idea where to start. I need help!!!!

Answer 1

Hi Tony,

 

Let's set up the problem like this:

 

1. x + x² = 56

2. Subtract 56 from both sides leaves us x +x² -56 =0; rearranging gives us x²+x-56=0 

3. Note that the equation in step 2 is a quadratic equation.

4. Factoring the equation gives us (x+8)*(x-7) = 0

5. Therefore x= -8, and x = 7.

 

Does that make sense?

 

Walter

Answer 2

let x be the number, so

 

x + x^2 = 56 

so x*(x+1) = 56

so x = 7