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25 votes
Solve:

7(2)^x=224

( help pls )

User Anudeep
by
5.3k points

2 Answers

6 votes

Answer: x = 5

Explanation:


7(2)^x=224

start by dividing 7 from both sides


(7(2)^x)/(7) =(224)/(7)


2^x=32

take the log of both sides


log(2^x) = log(32)

move the x to the left of the log


xlog(2) = log(32)

divide both sides by log(2)


x=(log(32))/(log(2))

use change-of-base formula


(log(a))/(log(b)) =logx_(b) (a)


x = log_(2) (32)

since
2^5 = 32, x = 5

Hope this helped :)

User Ebelisle
by
5.1k points
9 votes

Answer:

5

Explanation:

Original equation:


7(2)^x=224

Divide both sides by 7


2^x=32

Rewrite in log


log_232=x

You can do mental math to realize this equals 5, or plug this into your calculate (if it allows you to set the base), but if you can't do either, you can use the change of base formula:


log_ba=(log (a))/(log(b))

You get:


log_232=(log(32))/(log(2))

When you calculate using a calculator you should get 5

User Lzypenguin
by
4.9k points