When we look at an ordered pair, it will be presented as (x,y)
The first term, x (called the x-coordinate), will tell us how far we should count outwards from 0 (The Origin). The second term, y (called the y-coordinate), will tell us how far we will count outwards from our x coordinate.
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So if he already biked 25 miles we can subtract 80 and 25 which will get a total of 55. if we divided 55 miles to the rest of the 5 days he will have to bike 11 miles each day