Question 557940
you need the constant of proportionality, k


the incomes are 9k and 7k (k does NOT stand for 1000)


9k : 7k ___ dividing by k ___ 9 : 7


"The difference in their weekly incomes is $200" ___ 9k - 7k = 200 ___ 2k = 200 ___ k = 100


9k = 900

7k = 700