Let's try to get something that would work for just 5 for now. Any of these numbers would leave a remainder of 1 when divided by just 5: 6, 11, 16, 21, 26, 31, 36, 41, 46, 51, 56, 61, 66, 71, 76, 81, 86, ... Notice that they all look like 5*(something) + 1. Basically, they are all multiples of 5 plus 1.
Let's see what would work for just 8: 9, 17, 25, 33, 41, 49, 57, 65, 73, 81, 89, ...
Are there any matches... AHA! It's 81. This is the lowest positive integer greater than 1 that follows the rule for both 5 and 8.
In order to use a graph to write an equation, you first need to have plot points. Pick 2 points on the line if there isn't already any on the graph. After you find two points, find the slope. (Formula: y = mx + b) After you solve the slope, try finding the y-intercept. (Meaning: when x = 0, solve for y) The y-coordinate when you solve it is the value of "b" in the equation. (REMEMBER: y = mx + b) If you have any questions about the formula or the directions, remember to ask! Cheers, mimiisawesome5