## Precalculus: Mathematics for Calculus, 7th Edition

$Evaluate$ $the$ $expression$ $without$ $using$ $a$ $calculator:$ $\log_2 128$ Rewrite 128 as $2^7$ [Note: $2^7 = 2\times2\times2\times2\times2\times2\times2 = 128$] $$\log_2 2^7$$ Use the Third Property of Logarithms: $\log_a a^x = x$ $$\log_2 2^7 = 7$$