A book has 240 pages and each day 10 pages are read. The number of pages left, p, is given as a
function of d, the time in days, where
p = 240 – 10d . Graph the equation, then use its
x-intercept to determine when the book will be
finished?

24 days is the answer

Step-by-step explanation:

If the book is 240 pages and each day 10 pages are read you could easily divide 240 by 10 and get 24.   However, you need to use the formulas for your answer I suppose.  So, to get the  x-intercept this is what you do.  You have to use the slope-intercept form y = mx+b  where m=-10 and b = 240 so you end up with y = -10x+240

So now you solve for x-intercept

0 = -10d+240

subtract 240 from both sides so       0 = -10d + 240

                                                         -240              -240

you are left with -240 = -10d.  Now simplify and divide each term by -10     -240/-10 = 24 and -10d/-10 = d

   you are left with d = 24 or 24 = d

You graph the equation by placing a point at  240 on the y axis and 24 on your X-axis.