I don’t understand this, someone help me on this please.

Use the frequency distribution, which shows the number of american voters (in millions) according to age, to find the probability that a voter chosen at random is in the 18 to 20 years old age range. ages frequency 18 to 20 5.9 21 to 24 7.7 25 to 34 20.4 35 to 44 25.1 45 to 64 54.4 65 and over 27.7 the probability that a voter chosen at random is in the 18 to 20 years old age range is nothing. (round to three decimal places as needed.)

Whats are the trickiest steps to do when adding or subtracting rational expressions? how does knowledge of rational numbers u in adding and subtracting rational expressions?

What is the value of p in the equation y^ = -4x?