Respuesta :

Answer:

[tex]a=\frac{\ln \left(67\right)}{2\ln \left(3\right)}+8[/tex]

[tex]a = \frac{log 67}{2log3} +8[/tex]

Step-by-step explanation:

[tex]9^{a-8} +7=74 \\\\\mathrm{Subtract\:}7\mathrm{\:from\:both\:sides}\\\\9^{a-8}+7-7=74-7\\\\Simplify\\9^{a-8}=67[/tex]

Apply exponents rules

[tex]\left(a-8\right)\ln \left(9\right)=\ln \left(67\right)\\\\Solve \\\\a=\frac{\ln \left(67\right)}{2\ln \left(3\right)}+8[/tex]

Step 2:

[tex]9^{a-8}+7=74\\[/tex]