Develop two linear equations to represent the savings of these two people:
Raul: rl=$350 + $15x
Ruth: rh=$200 + $25x
In both cases, x represents the number of weeks elapsed.
When will these two people have saved up the same amount? Set rl = rh and solve for x, the number of weeks elapsed:
$350 + $15x = $200 + $25x
$150 = $10x gives us x= 15. Their savings will be equal after 15 weeks.