SOLUTION: Find the root of the quadratic equation. x^2-8x+15=0

Algebra ->  Complex Numbers Imaginary Numbers Solvers and Lesson -> SOLUTION: Find the root of the quadratic equation. x^2-8x+15=0      Log On


   

Question 263314: Find the root of the quadratic equation. x^2-8x+15=0
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
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%28600%2C600%2C-6%2C6%2C-6%2C6%2Cx%5E2+-+8x+%2B+15%29

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.