Question

According to the Fundamental Theorem of Algebra, 4x²+11x-20=0 has two solutions. How many of those solutions are integers?

Answer 1

Factor the quadratic:
4x² + 11x − 20 = (x + 4)(4x − 5)

So the solutions are x = −4 and x = 5/4. Only −4 is an integer, so 1 solution is an integer.