How do you solve #8x^2+32x-24# by completing the square?

1 Answer
Mar 20, 2017

Answer:

#x = -2 +sqrt 7, -2 - sqrt 7#

Explanation:

#8 x^2 + 32 x - 24 =0#

reduce coefficient #x^2# to 1 by dividing with #8#
#x^2 +4x -3 = 0#

consider coefficient of #x# and divide by 2 then make a parentesis and square them, then square the number in parentesis and deduct it in the equation.
#(x + 2)^2 - (2)^2 - 3 = 0#
#(x + 2)^2 - 4 - 3 = 0#
#(x + 2)^2 - 7 = 0#
#(x + 2)^2 = 7#
#(x + 2) = +-sqrt 7#
#x = -2 +-sqrt 7#

#x = -2 +sqrt 7, -2 - sqrt 7#