How do you solve 2^ { m + 1} + 9= 44?

3 Answers
Mar 3, 2018

m=log_2(35)-1~~4.13

Explanation:

We start by subtracting 9 from both sides:
2^(m+1)+cancel(9-9)=44-9

2^(m+1)=35

Take log_2 on both sides:
cancel(log_2)(cancel(2)^(m+1))=log_2(35)

m+1=log_2(35)

Subtract 1 on both sides:
m+cancel(1-1)=log_2(35)-1

m=log_2(35)-1~~4.13

Mar 3, 2018

m~~4.129 (4sf)

Explanation:

2^(m+1)+9=44

2^(m+1)=35

In logarithm form, this is:

log_2(35)=m+1

I remember this almost as keep 2 as the base and switch the other numbers.

m=log_2(35)-1

m~~4.129 (4sf)

Mar 3, 2018

m=(log35-log2)/log2

Explanation:

2^(m+1)+9=44

2^(m+1)=44-9=35

log (2^(m+1))=log35" " (taking the logarithm base 10 on both sides)

log(2^m * 2)=log35

log2^m +log2=log35

log2^m=log35-log2

mlog2=log35-log2

m=(log35-log2)/log2