1. To find slope use the slope equation which would be (3 - -1)/ (5-3). The slope is m = 4\2 which is m = 2
2. Plug in one of the points to find the y-intercept. Using the point (5,3) , you would plug this point into the slope intercept equation, along with the slope which was found. 3= (2 x 5) +b. Solving this equation b=-7
I’m not 100% sure but i think by what i learned that you would use a number line to measure to the number than the closest number of the time your looking for would be looking for.