Question

Find an equation that has -5 and 8 as solutions. Write your equation in standard form. For example, 4 and -3 are solutions to x^2-x-12=0.

Answer 1

(x+5)(x-8) = 0
x = -5 is a solution (makes the first factor zero)
x = 8 is a solution (makes the second factor zero)

Answer 2

now expand it to standard form

Answer 3

Another way to do this:

Find the sum of the solutions. That is 3.
Find the product of the solutions. That is - 40.
Now, reverse the sign of the sum of the solutions. That is - 3.
Then, your equation is \[x^{2} - 3x -40=0\]