This is esay to do when you realize the the speed of mowing is addtive. This is if John mows at 1 lawn / (2/3) hour and Gerge mows at 1 lawn / 1hour, the total speed of mowing is:
1 / (2/3) + 1 = 3/2 + 1 = 5/2
=> 5/2 of lawn per hour
Now, the time is calcualted as the amount of lawn divided by the speed:
1 lawn / (5/2 lawn/hour) = 2/5 hour.
Answer: 2/5 of an hour.
Assume your line starts at zero, your first point is (-3,5) meaning your have a slope of 5/-3
[ f(x) = 5/-3x + b]
X=number of years after 2000.
y=percentage of residents (still) reads newspapers for information
initial value (= y-intercept) = percentage in 2000 = 54%
slope = increase each year = -1.7% (because it is a decrease)
the slope intercept form of the equation is therefore:
y=slope(x)+initial value, or
y=-1.7x+54 (in %)
one tip:
Example: 4 - (-3)
it instantly becomes positive because the negatives are close to each other as shown.
hope that helps :)