Answer:
Approx 6 weeks
Step-by-step explanation:
Represent Sabrina's savings by S(w) = $112 + ($10/wk)w, and
Rex's by R(w) = $84 + ($15/wk)w.
Equate these to determine the number of weeks it will take for their respective savings to become equal:
$112 + ($10/wk)w = $84 + ($15/wk)w
first, combine the constant dollar amounts:
$112 - $84 + ($10/wk)w = ($5/wk)w
next, subtract ($5/wk)w from both sides, obtaining:
$28 = ($5/wk)w
Finally, divide both sides by ($5/wk)w, obtaining:
w = 5.6 weeks
Thus, the answer here is that Rex will have more money saved than Sabrina after 5.6 weeks; we could round that off to 6 weeks.
