Can someone pls help me with this i will mark brainliest

You have the correct answer. Nice work.

Explanation:

Let's say Phil passes his brother at a sign post, and let's say the sign post is x miles into the 6 mile hike. This means 0 < x < 6.

Once Bill reaches the sign post, he turns around to walk back x miles. His faster brother Phil bikes the remaining 6-x miles to the trail end, before coming back to bike an additional 6 miles to get to the trailhead again. Phil arrives back at the same moment Bill does.

Overall, Phil travels 6-x+6 = 12-x miles in the same amount of time Bill walks back x miles. I recommend drawing out a number line diagram to see why this is the case.

For Bill, we have this equation

distance = rate*time

x = r*t

r = x/t

Phil has the equation

distance = rate*time

12-x = (3r)*t

Notice that Phil's rate is three times that of Bill. The t is the same for both brothers because they travel in the same timespan.

Plug in r = x/t and solve for x. The t variables divide and cancel.

12-x = 3*(r)*t

12-x = 3*(x/t)*t

12-x = 3x

12 = 3x+x

4x = 12

x = 12/4

x = 3

Phil passed Bill at the 3 mile marker.

This is why the answer is choice B.

-12 > a

step-by-step explanation:

-11 > 1 + a

subtract 1 from each side

-11-1 > 1-1+a

-12 > a