How do you solve using the completing the square method #2x^2 = 2x + 15#?

1 Answer
Apr 29, 2017

Answer:

Solution : #x= 1/2(1 + sqrt(31)) and x= 1/2(1 - sqrt(31))#

Explanation:

# 2x^2 =2x+15 or 2x^2 -2x= 15 or 2(x^2-x) =15 or (x^2-x) = 15/2#or

#(x^2-x +(1/2)^2) -1/4= 15/2 or (x-1/2)^2 = 15/2+1/4 or (x-1/2)^2 = 31/4# or
# (x-1/2)= +-sqrt(31/4) or x = 1/2+- sqrt(31)/2 or x = 1/2(1 +- sqrt(31))#

Solution : #x= 1/2(1 + sqrt(31)) and x= 1/2(1 - sqrt(31))# [Ans]