Chapter 6 - Logarithmic Functions - 6.6 Solving Logarithmic Equations - 6.6 Exercises - Page 534: 7

$x = 19.6$

$\log (5x + 2) = 2$ $\log_{10} (5x + 2) = 2$ $10^{2} = 5x + 2$ $100 = 5x + 2$ $100 -2 = 5x$ $98 = 5x$ $x = 19.6$ Check: $\log (5(19.6) + 2) \overset{?}{=}2$ $\log (98 + 2) \overset{?}{=}2$ $\log_{10} (100) \overset{?}{=}2$ $\log_{10} 10^{2} \overset{?}{=}2$ $2 = 2$