The factors of 2160 are 1, 2160, 2, 1080, 3, 720, 4, 540, 5, 432, 6, 360, 8, 270, 9, 240, 10, 216, 12, 180, 15, 154, 16, 135, 18, 120, 20, 108, 24, 90, 27, 80, 30, 72, 36, 60, 40, 54, 45, 48 These are all divisors of 2160 but only 30 are multiples of 3. The ones that are NOT are 1, 2, 4, 5, 8, 10, 16, 20, 40 and 80
You can also do this using prime factors 2x2x2x2x3x3x3x5 = 2160 but it is harder to explain.
First, you find the slope by using the slope formula and get 0. Now, choose one coordinate and plug it into the equation y = mx + b along with the slope. If you chose the first coordinate, the equation would be -1 = (0)(5) + b. After solving for b (the y-intercept) you would get -1. Lastly, you rewrite the equation as y = -1.
Explanation: If he washes 75 cars in 5 days; and you need to find how many days it takes to wash 90 you do 75 divided by 5 which is 15; so he washes 15 cars in a day, then do 90 divided by 15 which is 6 days
