you don't need to know this for real life situations but for school you do need to know it, i dont know how to do this but here's a link to the same question you have but it's explained on how to solve it
https://www.wyzant.com/resources/answers/499729/fireworks_can_go_up_to_1000_feet_in_around_3_seconds_what_s_is_it_s_average_vertical_speed_in_feet_per_second_and_miles_per_hour
((Also i'm a fellow ARMY as well =) ))
The answer would be: X=26
The lines are parallel.
In order to figure this out, let's start off by simplifying both equations as much as we can:
2y = 16 + 4x
Divide by 2
y = 2x + 8
Remember that the slope of that equation is '2' since 'm' in the equation y = mx + b represents slope.
Simplify the next equation:
6y - 30 = 12 x
6y = 12x + 30
Divide by 6:
y = 2x + 5
As you can tell, this line also has a slope of 2.
Parallel lines is defined as two lines that have the same slope. Knowing this, we can infer that these two lines are parallel.
-T.B.
Okay, so first you draw a picture and let x be the distance from point D to the rest stop. Then the distance from point to the rest stop is 8 - x
You know that the length of the new trail is y + z, where y is the distance from Ancaster to the rest stop and z is the distance from Dundas to the rest stop.
Now by the Pythagorean theorem, y^2 = 4^2 + x^2 and z^2 = 6^2 + (8 - x) ^2
So take square roots of these, add them, and minimize.
Note: I am assuming the path is perfectly straight, otherwise this approach fails.