Equation of a line is given by y - y1 = m(x - x1) where m is the slope and (x1, y1) is any point on the line.
y - (-2) = 4(x - 3)
y + 2 = 4x - 12
y = 4x - 12 - 2
y = 4x - 14
The projectile's horizontal and vertical positions at time
are given by


where
. Solve
for the time
it takes for the projectile to reach the ground:

In this time, the projectile will have traveled horizontally a distance of

The projectile's horizontal and vertical velocities are given by


At the time the projectile hits the ground, its velocity vector has horizontal component approx. 176.77 m/s and vertical component approx. -178.43 m/s, which corresponds to a speed of about
.
It's m. All you have to do is distribute
You have a fraction of 3/2. 3/2=1.5
Therefore, she needs 1.5 gallons of blue paint per 1 gallon of yellow paint.