Question

Solve the exponential equationD%20" id="TexFormula1" title=" {10}^{ - x} = {7}^{4x} " alt=" {10}^{ - x} = {7}^{4x} " align="absmiddle" class="latex-formula">

Answer 1

$10^{-x}=7^{4x}\\ \ln 10^{-x}=\ln 7^{4x}\\ -x \ln 10=4x\ln 7\\ -x \ln 10-4x\ln 7=0\\ x(-\ln 10-4\ln 7)=0\\ x=0$