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) =