Step-by-step explanation: It's pretty basic math, you have your flat fee ($50) and then you add your variable 2x. 2 is multiplied by x so you can figure out the amount that it costs to ride the rides.
Ask her why she is crying. If she explains why, listen and comfort her. If she says to "go away" or "i don't want to talk about it," give her space and come back later. She needs to let it out, so have patience :)