Jimmy and rick are practicing knot-tying for their rock climbing training. the number of knots that jimmy can complete in x days is modeled by the function f(x) = 6x + 10, and the number of knots rick can complete in x days is modeled by the function g(x) = 4x + 15. after x days, the function that models how many more knots jimmy can complete than rick is given by h(x) = x - .

2x - 5

Explanation:
For Jimmy, the function that models his work is:
f (x) = 6x + 10

For Rick, the function that models his work is:
g (x) = 4x + 15

To get the how many knots Jimmy can complete than Rick, all you have to do is subtract the function of Rick's work from the function of Jimmy's work.
This means that:
h (x) = f (x) - g (x)
h (x) = (6x+10) - (4x+15)
h (x) = 6x + 10 - 4x - 15
h (x) = 2x - 5

Hope this helps :)