Please help I'm literally so yeet lol. What is the difference between "y=f(x)" and a number such as "f(a)"?

Asix-sided number cube is rolled twice. what is the probability that the first roll is an even numbe and the second roll is a number greater than 4?

Write the percent as a fraction or mixed number in simplest form. 0.8%

You are riding your bike and notice the square sign above. you mentally draw a straight line from point a to c. describe the angle relationship between dca and bca