Answer
H) $-3y = 29$
Work Step by Step
F) $3x + 6y = 0$
$3x + 6y - 3x = 0-3x$
$6y = -3x$
$6y/6 = -3x/6$
$y = -x/2$
This line is not a horizontal line.
G) $2x+7 = 0$
$2x + 7 - 7 = 0 - 7$
$2x = -7$
$2x/2 = -7/2$
$x = -3.5$
This is a vertical line (not a horizontal line).
H) $-3y = 29$
$-3y/-3 = 29/-3$
$y = -29/3$
This is a horizontal line.
I) $x-2y = 4$
$x - 2y -4 +2y = 4 -4 + 2y$
$x - 4 = 2y$
This is not a horizontal line.
