What two numbers multiply to 864 and add up to 48?

Answer 1

912

Answer 2

As Ironnica knows, I love questions like this!

So, I would set up two equations:

xy=864

x+y=48

By using subtraction on the second equation, y=48-x

Substituting this in the first equation, x(48-x)=864

Simplifying that gives -x2+48x=864

I'm going to subtract 864 from both sides to get -x2+48x-864

You might notice that there is now a quadratic, meaning we can use the quadratic formula! (Look it up if you don't know, it is very helpful in solving these kinds of problems)

The answer is x = 24±12i√2

If x = 24-12i√2, then y would equal 24+12i√2