y2-y1/x2-x1 take the y coordinate of the second pair of coordinates and subtract it by the y coordinate of the first pair, then take the x coordinate from the second pair of coordinates and subtract it from the x coordinate from the first pair. then put your answer from the y coordinate over the answer from the x coordinates. 1 - 13 / 8 - 2, then you get -12/6, which simplifies to 2.
If you are answering a question or about how many pages he has in his book, it is 550 pages in his book total. If it's how much longer Naoya will have to read to finish their book it is 10 hours.
