well, let's take a look at Henry's equation, let's make a table
to get the equation of any straight line, we simply need two points off of it, so let's use those two then for Henry
now, let's take a peek at Tasha's equation, hmmm y = 10x + 12
at 0 hour, namely when x = 0, Tasha's balloon was at y = 10(0) + 12 => y = 12
was 12 miles from town, whilst we know Henry's was 20 miles from town, so Henry's balloon was farther.
now, the slope in an equation, is simply the rate of change, so the larger the slope, the larger the rate of change or namely the faster it moves.
well, hell Tasha's slope is "10", whilst Henry's is "14", so Henry's balloon is going faster.