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:

$2+x=72$

$x=70$