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24 votes
24 votes
PLS HELP!!
what is the value of x?
log2(x+7) = 2​

PLS HELP!! what is the value of x? log2(x+7) = 2​-example-1
User Lauhub
by
2.9k points

2 Answers

9 votes
9 votes

Answer: Choice A) -3

Work Shown:


\log_(2)(x+7) = 2\\\\x+7 = 2^2\\\\x+7 = 4\\\\x = 4-7\\\\x = -3\\\\

Which leads us to choice A. In the second step, I used the rule that
\log_b(y) = x is equivalent to
y = b^x. For each equation, the b is the base. Note how logs undo exponents and vice versa.

User Donfuxx
by
2.7k points
17 votes
17 votes

Answer:

-3

Explanation:

log2(x+7) = 2​

Raise each side by base 2

2^log2(x+7) = 2^2​

x+7 = 4

Subtract 7 from each side

x+7-7 = 4-7

x=-3

User PeterClemmensen
by
2.7k points