Note the equation/formula:____________________________ d * r = t ;
_____________________________ in which:
_____________________________ d = distance = 84 ft.
r = rate = 12 ft / sec
t = time = ?_______________________________To find the "time" we can rearrange the equation:
_______________________________________ d = r * t ;
_______________________________________ Divide EACH SIDE of the equation by "r" ; to isolation "t" on one side of the equation; to create an expression to find the time for the given distance and rate; which we will then do by plugging in our given values for "d" (distance) and "r" (rate) ;
_______________________________________ d / r = (r * t) / r ;
_________________________ to get : d / r = t ;
_________________________ โ t = d / r ;
_________________________Now, plug in our given values for "d" and "r" ; to solve for "t" ;
______________________________________________________ โ t = 84 ft / (12 ft / sec) ;
= 84 ft รท

;
= 84 ft *

;
= {

} sec. ;
___________________________________________________ โ t = 7 sec. {that is; "7 seconds" }.
______________________________________________________