Seth and karen are college students who take on different jobs for income. seth needs $750 for expenses and savings each month; karen needs $700. seth has a part-time job where he earns $7.50 per hour. he also mows lawns and earns $15 per lawn that he mows. his monthly earnings can be expressed with the equation 7.50x + 15y = 750, where x is the number of hours seth works and y is the number of lawns he mows. karen has a part-time job babysitting, where she earns $6 per hour. she also walks dogs and earns $4 per dog that she walks. her monthly earnings can be expressed with the equation 6x + 4y = 700, where x is the number of hours karen works and y is the number of dogs she walks.