Solve 2x2 + 12x - 14 = 0 by completing the square, options: A. 2 (x + 6) 2 = 26; x = - 6 + square root 13, x = - 6 - square root 13 B. 2 (x + 6) 2 = 20; x = - 6 + square root 20, x = - 6 - square root 20 C. 2 (x + 3) 2 = 32; x = 1, x = - 7 D. 2 (x + 3) 2 = 32; x = 13, x = 19

Question

Mathematics

Karma Carroll

11 September, 19:13

Solve 2x2 + 12x - 14 = 0 by completing the square, options: A. 2 (x + 6) 2 = 26; x = - 6 + square root 13, x = - 6 - square root 13 B. 2 (x + 6) 2 = 20; x = - 6 + square root 20, x = - 6 - square root 20 C. 2 (x + 3) 2 = 32; x = 1, x = - 7 D. 2 (x + 3) 2 = 32; x = 13, x = 19

+5

Answers (1)

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Kailyn Burns · Answer 1

I just solved this one

anothe way is undistribute the 2 first and move - 14 to side

2 (x^2+6x) - 14=0

comlete the squer inside and add negative

2 (x^2+6x+9-9) - 14=0

factor perfect square

2 ((x+3) ^2-9) - 14=0

distribute

2 (x+3) ^2-18-14=0

2 (x+3) ^2-32=0

add 32 both sides

2 (x+3) ^2=32

divide 2

(x+3) ^2=16

sqrt both sides

x+3=+/-4

minus 3

x=-4-3 or 4-3

x=1 or - 7

answer is C