SOLUTION: Solve the equation x^2 + 8x - 2 = 0 using both the quadratic formula and completing the square method.

Algebra.Com
Question 201740: Solve the equation x^2 + 8x - 2 = 0 using both the quadratic formula and completing the square method.
Answer by Alan3354(69443)   (Show Source): You can put this solution on YOUR website!
Solve the equation x^2 + 8x - 2 = 0 using both the quadratic formula and completing the square method.
-------------
Complete the square:
x^2 + 8x - 2 = 0
x^2 + 8x = 2
x^2 + 8x + 16 = 18
(x+4)^2 = 18
x+4 = +/-sqrt(18)
x = -4 +/- 3sqrt(2)
-------------------
Solved by pluggable solver: SOLVE quadratic equation (work shown, graph etc)
Quadratic equation (in our case ) has the following solutons:



For these solutions to exist, the discriminant should not be a negative number.

First, we need to compute the discriminant : .

Discriminant d=72 is greater than zero. That means that there are two solutions: .




Quadratic expression can be factored:

Again, the answer is: 0.242640687119285, -8.24264068711928. Here's your graph:




RELATED QUESTIONS

Solve the equation x^2 + 8x + 2 = 0 using both 1. The Quadratic Formula 2.... (answered by MathLover1)
Please show me how to Solve the equation x2 + 8x – 2 = 0 using both The quadratic formula (answered by haileytucki,jim_thompson5910)
Can someone please help? 3x^2+8x-2=0 1. Solve using Quadratic formula 2. Solve using (answered by Edwin McCravy)
I need this problem solved by both quadratic formula and Completing the square. Thank... (answered by Fombitz)
Solve by completing the square and quadratic formula: 1.) 3x^2+8x+5=0 2.)... (answered by josgarithmetic,MathTherapy)
Could you please help me solve this quadratic equation using completing the square... (answered by Alan3354)
1) Solve the quadratic equations by factoring: 5x² = 125 2) Solve the quadratic... (answered by checkley71)
I cant figure this one out. Please help. Solve the equation x2 + 8x – 2 = 0 using both (answered by Mathtut)
Could you please help solve this quadratic equation using completing the square method? (answered by lwsshak3,josgarithmetic,josmiceli)