SOLUTION: solve the equation by completing the square x2+3x-9=0.
Algebra.Com
Question 274717: solve the equation by completing the square x2+3x-9=0.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
solve the equation by completing the square
x^2+3x-9=0
---
x^2 + 3x + ? = 9 + ?
----
Complete the square:
x^2 + 3x + (3/2)^2 = 9 + (3/2)^2
---
Factor:
(x+3/2)^2 = (36/3)+(9/4) = 45/4
---
x + (3/2) + (9/2)sqrt(5) or x+(3/2) = (-9/2)sqrt(5)
----
x = (-3+9sqrt(5))/2 or x = (-3-9sqrt(5))/2
===============================
Cheers,
Stan H.
RELATED QUESTIONS
solve equation by completing the square
x2 + 4x - 36 =... (answered by ewatrrr,nerdybill)
Solve by completing the square:
x2 + 6x + 4 = 0
(answered by jake_6233)
Solve by completing the square:
x2 + 6x + 4 =... (answered by tutorcecilia,atif.muhammad)
Solve by completing the square.
x2 + 2x – 15 = 0
(answered by Earlsdon)
Solve by completing the square.
x2 – 2x – 15 = 0
(answered by funmath)
Solve by completing the square:
x2 + 6x + 2 = 0
(answered by jim_thompson5910)
Solve by completing the square:
x2 + 8x + 13 = 0
(answered by stanbon)
Solve by completing the square.
x2 – 2x – 63 = 0
(answered by Mathtut)
Solve by completing the square
x2 + 6x – 4... (answered by richwmiller)