3) Both Sabrina and Rex are saving money for a big purchase. Sabrina currently

(week 0) has $112 saved, and Rex has $84 saved. Sabrina saves $10 each week

and Rex saves $15 each week. After how many weeks will Rex have more money

saved than Sabrina?

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.