Question 263314
x^2 - 8x + 15 is the equation.


3*5 = 15
3+5 = 8


equation can be factored to (x-5)*(x-3) = 0


this is because (x-5) * (x-3) = x*(x-3) - 5*(x-3) = x^2 - 3x - 5x + 15 = x^2 - 8x + 15.


solve for x to get x = 5 and x = 3


roots of the equation are x = 5 and x = 3


graph of this equation looks like the following:


{{{graph(600,600,-6,6,-6,6,x^2 - 8x + 15)}}}


you can see that the graph of the equation crosses the x-axis at x = 3 and x = 5.


those are the values of x when y = 0.