x^2+5x-36

I assume you want this expression to be factored. Here is the process:

Factor the values of the two end terms each into two factors. Since there is no numerical value before the x^2, you only need to factor the 36 (-1,36 or -36,1 or -6,6 or -9,4 or -4, 9 or -12,3 or -3,12)

Which combination would sum to the middle value of 5?

I hope this helps you to understand the process.