for y=1/2x +6
the slope of a parallel line: (will be the same) 1/2
the slope of a perpendicular line: -2 (we change the sign and the revert the fraction)
for x=-4.2
the slope of a parallel line: undefined (because it is a vertical line)
the slope of a perpendicular line: 0
for 3x+4y=3, we need to put it in the slope-intercept form that will be y=-3/4(x-1)
the slope of a parallel line: -3/4
the slope of a perpendicular line: 4/3 (we change the sign and the revert the fraction)
for y=3
the slope of a parallel line: 0 (because it is horizontal)
the slope of a perpendicular line: undefined
for y=x
the slope of a parallel line: 1
the slope of a perpendicular line:-1
