Modifying the Slope and the Y-Intercept

A linear function (a function that graphs as a line) can be written in the form f(x) = mx + b, where m and b are real numbers.

If x is fixed, what happens to the value of f(x) if m increases by one? if m decreases by two? if m changes by n?

If x is fixed, what happens to the value of f(x) if b increases by one? if b decreases by two? if b changes by n?