SOLUTION: Find the number of real roots. x^2-7x+9=0

Algebra ->  Square-cubic-other-roots -> SOLUTION: Find the number of real roots. x^2-7x+9=0      Log On


   

Question 22736: Find the number of real roots.
x^2-7x+9=0
Answer by Earlsdon(6294) About Me  (Show Source):
You can put this solution on YOUR website!
Find th real roots of:
x%5E2+-+7x+%2B+9+=+0 Solve using the quadratic formula: x+=+%28-b%2B-sqrt%28b%5E2-4ac%29%29%2F2a a = 1, b = -7, and c = 9
x+=+%28-%28-7%29%2B-sqrt%28%28-7%29%5E2-4%281%29%289%29%29%29%2F2%281%29 Simplify.
x+=+%287%2B-sqrt%2849-36%29%29%2F2
x+=+%287%2B-sqrt%2813%29%29%2F2
The roots are:
x+=+%281%2F2%29%287+%2B+sqrt%2813%29%29
x+=+%281%2F2%29%287+-+sqrt%2813%29%29