Yak Travel Agency arranges trips for climbing Mount Everest. For each trip, they charge an initial fee in addition to $\$0.15$ for each vertical meter climbed. For instance, the price for climbing all the way to the summit, which is $3500$ meters above the base of the mountain, is $\$645$. Let $F(d)$ denote the fee of a trip $F$ (measured in dollars) as a function of the vertical distance climbed $d$ (measured in meters). **Write the function's formula.** $F(d)=$ [[☃ expression 1]]