Answer:
Rate of change = 4
Explanation:
The rate of change of a linear equation is equal to its slope. The slope of a linear equation in slope-intercept form (y = mx + b) is equal to the coefficient of the x term (m).
In the equation y = 4x + 9 while comparing to y = mx + c, we get the coefficient of the x term is 4. Therefore, the rate of change of the equation is 4.
In other words, for every 1 unit increase in x, y will increase by 4 units.