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Two similar questions I can't wrap my mind around

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by Em_Bee_AyeDOTcom » Sat Mar 06, 2010 11:52 am
If someone would be so kind to go over the steps to solve these two problems I'd greatly appreciate it.

I have an explanation for one of the problems but their method does not go into enough detail for me to understand the explanation fully.

Here are the two problemsf:

1) Solve for x

3^x - 3^(x-1) = (3^13)(2)

2) Solve for x

2^x - 2^(x-2) = 3(2^13)
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Source: — Data Sufficiency |

by hai1 » Sat Mar 06, 2010 1:41 pm
1) Solve for x

3^x - 3^(x-1) = (3^13)(2)

3^x(1-1/3)=(3^13)(2);

3^x(2/3)=(3^13)(2);

3^x(=(3^14); (divide by 2/3 on both sides)

x=14;

2)2^x - 2^(x-2) = 3(2^13)

In a similar fashion as 1, x= 15
as 2^x (1- 1/4) = 3(2^13)
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