The rate of change of a linear equation (first degree) is equivalent to the slope of a line. Slope is described as the vertical movement (rise) of the line over its horizontal counterpart (run). In determining the rate of change or slope (m) given 1 data point (x',y'), point-slope form is applicable. Point-slope form is: (y-y') = m (x-x'). Substitute the given point (-5,-1) in the equation. By substitution, [y-(-1)] = m [x-(-5)]. Re-arranging the equation, the rate of change or slope is, m = (y+1)/(x+5).
Hey there :)
To find the slope with <em>two points</em> we will need to use the equation 
( 3 , -20 ) ( 5 , 8 )
Here is what the equation should look like when replaced with the numbers (<em>it will be a fraction</em>) :
We know that <em>two negatives</em> cancel out and make a positive, so the numerator would actually be 8 + 20.
Solve the fraction and we get 
28 <em>divided</em> by 2 is 14. The slope is 14.
You can combine the same numbers with the same variables using the operation sign for each. For example, using your equation, you would combine the 3n and 4n which is 7n. So your equation would be
7n - 2
The probability that will not rain today is: 85%
100% - 15% = 85%
The correct answer is A
