N + d = 30
0.05n + 0.10d = 2.20
^^ ur system of equations
For a survey like this, you want to take a random sample. It would be a good idea to use an alphabetical list of the students. Then, you could randomly select students from the list.
The principal would want to avoid surveying all the same type of students. For example, don't just ask the athletes.
The answer is undefined
The slope of a line can be positive, negative, zero, or undefined. A horizontal line has slope zero since it does not rise vertically (i.e. y1 − y2 = 0), while a vertical line has undefined slope since it does not run horizontally (i.e. x1 − x2 = 0).
