Question

How many real number solutions does the equation have?
y=2x^2-20x+50
A. One solution
B. Two solutions
C. No solutions
D. Infinitely many solutions

Answer 1

looking at the highest degree (in this case 2) gives you an idea of how many solutions there are, but there could be less (i.e. double or triple roots or imaginary roots).

I will solve the equations so that you can see this:

(2x -10)(x-5) = 0
x = 5 and x = 5

so there is only 1 solution.