I need to solve the equation : $\ln(x+2)+\ln(5)=\lg(2x+8)$
With the change of base formula we can turn this into: $\ln(x+2)+\ln(5)=\frac{\ln(2x+8)}{\ln(10)}$
We can also simplify the LHS with the product rule so: $\ln(5(x+2))=\frac{\ln(2x+8)}{\ln(10)}$
Solving the fraction gives us: $\ln(10) \, \ln(5(x+2)) = \ln(2x+8)$
Simplifying the LHS even further: $\ln(5x+10)^{\ln(10)}=\ln(2x+8)$
We can then see that $(5x+10)^{\ln(10)}=2x+8$
And this is where I get stuck, I can't seem to figure out how to expand this term. Does anyone know how to solve this?
You can find answer by researching of graphic of functions,I don't think you can get it by algebric method