There is a video on khanacademy, search "rationalize the denominator." Then instead of getting the answer you will learn how to do it and be able to do it on other problems in the future.
Slope: -4/3
y+1=-3/4(x-4)
y+1= -3/4 +3
y= -3/4x +2
The answer is 5/13.
Walking(7) + Biking(3) = 10 students
10 students out of 26 total students = 10/26
Simplified is 5/13