Question #3efa2

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Answer 1 · 2017-01-18T01:15:02

#x=70#

Repeated addition is multiplication. Thus:

#overbrace(2^x+2^x+2^x+2^x)^("repeated 4 times")=2^72#

#4(2^x)=2^72#

Let's write this all with the same base:

#2^2(2^x)=2^72#

Using the rule #a^b(a^c)=a^(b+c)#:

#2^(2+x)=2^72#

Equating the powers:

#2+x=72#

#x=70#