Jordan has a jar of quarters. when he has 60 quarters in the jar, the jar weighs 52 ounces. when get is 125 quarters the jar, there jar weighs 65 ounces. what is the weigh of the empty jar?

Think of 2 points:  (60, 52) and (125, 65).
                                                                     65-52             13         1
The slope of the line thru these pts is   m = = = ---
                                                                      125-60           65         5

Then the equation of the line is found from   y = mx + b, which here is
                                                                     125=(1/5)(65) + b

Then 125 - 13 = b, or 112 = b

The equation of this line is then y = 5(x)  + 112.

Notice that when x =, the jar is empty.  It weighs 112 oz.