The formula for determining how long a hike will take is t=12(d+h) , where d is the distance in miles and h is the elevation gain in thousands of feet.

Solve for h.

To solve for h, we can rearrange the given formula:

t = 12(d + h)

First, let's isolate (d + h) by dividing both sides of the equation by 12:

t/12 = d + h

Now, we can subtract d from both sides to move it to the other side of the equation:

t/12 - d = h

Therefore, the formula for solving h is:

h = t/12 - d