Question 12582
Remember: Parallel lines have equal slopes.

Get your equations into the slope-intercept form: {{{y = mx + b}}} m is the slope.

1)
{{{2y = 3x + 4}}} Divide both sides by 2.
{{{y = (3/2)x + 2}}} The slope, m is 3/2

2)
{{{y - ax - 5 = 0}}} Add ax to both sides.
{{{y - 5 = ax}}} Add 5 to both sides.
{{{y = ax + 5}}} Compare with: {{{y = mx + b}}} a = m

From the first equation, we had m = 3/2, and, because these lines are parallel, they have the same slope. Therefore, a = 3/2