SOLUTION: hi! if S= a over 1-r find s when a=10 and r=1/2 find s when a=4 and r=1/5

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Question 128289: hi!
if S= a over 1-r find s when a=10 and r=1/2
find s when a=4 and r=1/5
Answer by JessicaGill(40) About Me  (Show Source):
You can put this solution on YOUR website!
if S=a%2F%281-r%29 find s when a=10 and r=1/2and find s when a=4 and r=1/5

Set up first problem and substitute values
s=10%2F%281-%281%2F2%29%29
Simplify 1-%281%2F2%29=1%2F2
Now we are at s=10%2F%281%2F2%29
There are two ways to do this and you will get the same answer.
1. Convert 1%2F2 to a decimal .50 and divide to get 20=s
2. Multiply 10 by the reciprical of 1%2F2 which is 2%2F1 and you will still end up with s=20
%2810%2F1%29%2A%282%2F1%29=20%2F1 or 20
2nd problem
s=4%2F%281-%281%2F5%29%29
First simplify 1-%281%2F5%29=4%2F5
Now there are two ways to cotinue as above
1. Convert 4%2F5 to a decimal .80 and divide 4%2F.80=5
OR
2. Multiply 4 by the reciprical of 4%2F5 which is 5%2F4
%284%2F1%29%2A%285%2F4%29=5
so s=5 for the second problem
Hope this helps!
Ms. G