Answer:
Ellen invested $60 and Bob invested $140
Step-by-step explanation:
let the two amounts invested by 3x and 7x
(notice 3x : 7x = 3 : 7 )
then 3x + 7x = 200
10x = 200
x = 20
then 3x = 3(20) = 60
and 7x = 7(20) = 140
60+140=200
In order to solve a proportion you need to cross multiply, so you would do:
4x20 and 9xX and you would get...
9x=80
then divide by nine to get
x=8.8888888889
which is technically 8.9
Comparative relationships between numbers
D if you take 6/25 = 24/100 then change to a decimal and get 0.24