SOLUTION: I have a question on this problem.....If r = 5z then 15 z = 3y, then r = ????? The answer is = y but to get there we divided by 3, my question lies on how did we come to use 3 ?

Algebra ->  Numeric Fractions Calculators, Lesson and Practice -> SOLUTION: I have a question on this problem.....If r = 5z then 15 z = 3y, then r = ????? The answer is = y but to get there we divided by 3, my question lies on how did we come to use 3 ?      Log On


   

Question 498259: I have a question on this problem.....If r = 5z then 15 z = 3y, then r = ?????
The answer is = y but to get there we divided by 3, my question lies on how did we come to use 3 ? Can you put another example problem like this one so i can see the relation to this problem?
Greatly appreciated.
-Paul
Answer by Theo(13342) About Me  (Show Source):
You can put this solution on YOUR website!
if r = 5z and 15z = 3y, then r = ?????
take 15z = 3y and solve for z.
you get:
z = 3y/15
not you take r = 5z and you substitute for z to get:
r = 5 * 3y/15 which becomes:
r = 15y/15 which becomes:
r = y