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41 votes
41 votes
4^x + 3 = 7 using the change of base formula log y =
log y/log b

User Onki
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1 Answer

22 votes
22 votes

Answer:

x=1

Explanation:

It's pretty obvious to see that x equals 1 after you subtract 3 from both sides, but this question specifies using change base, so:

log(b)a means log base b with a as the contents
1.
4^x+3-3=7-3


4^x=4


log(4)4^x=log(4)4 (both logs are base 4 in this case to free the x)


x=log(4)4

x=log(10)4/log(10)4 (both logs are base 10 in this case)

x=1

Change base is definitely unnecessary in this problem

User Sonja
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3.4k points