Solve 2x2 + 12x - 14 = 0 by completing the square.

Add 14 both sides

2x^2+12x=14

make term in front of x^2 1

divide both sid s by 2

x^2+6x=7

take 1/2 of 6 and square it and add to both sides (6/2=3 3^2=9)

x^2+6x+9=7+9

factor pefect square

(x+3) ^2=16

sqrt both sides

x+3=+/-4

minus 3

x=+/-4-3

x=4-3 or - 4-3

x=1 or - 7