SOLUTION: I need help with this problem please solve by completing the square x^2-9/2x-1/2=0 x^2-9/2x=1/2 (9/2/2)^2=(9/4)^2=81/16 x^2-9/2x+81/16=1/2+81/16 (x-9/2)^2=89/16 89/16 is whe

Algebra ->  Quadratic Equations and Parabolas  -> Quadratic Equations Lessons  -> Quadratic Equation Lesson -> SOLUTION: I need help with this problem please solve by completing the square x^2-9/2x-1/2=0 x^2-9/2x=1/2 (9/2/2)^2=(9/4)^2=81/16 x^2-9/2x+81/16=1/2+81/16 (x-9/2)^2=89/16 89/16 is whe      Log On


   



Question 464160: I need help with this problem please
solve by completing the square
x^2-9/2x-1/2=0
x^2-9/2x=1/2
(9/2/2)^2=(9/4)^2=81/16
x^2-9/2x+81/16=1/2+81/16
(x-9/2)^2=89/16
89/16 is where I get confused. Where do they get 89. This is where I need help to finish the equation and others as well. Thank you for you time and explanation

Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
solve by completing the square
x^2-9/2x-1/2=0
x^2-9/2x=1/2
(9/2/2)^2=(9/4)^2=81/16
x^2-9/2x+81/16=1/2+81/16 = 8/16 + 81/16 = 89/16
(x-9/2)^2=89/16
------------
x+-+9%2F2+=+sqrt%2889%29%2F4
x+=+9%2F2+%2B+sqrt%2889%29%2F4
x+=+9%2F2+-+sqrt%2889%29%2F4