Complete the square for 2x2 – 4x = 14? A. (2x – 2)2 = 30 B. (2x – 1)2 = 15 C. (x – 1)2 = 8 D. (x + 1)2 = 8

1 Answer
Shubh
Apr 16, 2018

C.

Explanation:

#2x^2-4x=14#
Firstly, divide the equation by 2 so that coeffecient of #x^2#=1
#x^2-2x=7#
Now, add the square of half the coeffecient of x both sides i.e.
#x^2-2x+(2/2)^2=7+(2/2)^2#
#x^2-2x+1=8#
as, #x^2-2x=8# is the identity of #(x-1)^2#
so, #(x-1)^2=8#
so correct answer is C.

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