Which of the following equations has only one solution? x2 + 4x + 4 = 0
x2 + x = 0
ox²-1=0

x² + 4x + 4 = 0

Step-by-step explanation:

x² + 4x + 4 = 0

( x + 2 )² = 0

x + 2 = 0

x = -2

x² + x = 0

x ( x + 1 ) = 0

x = 0 or x = -1

x² - 1 = 0

x² = 1

x = 1 or x = -1