# Math Help - logarithm

1. ## logarithm

5^(2x) + 5^(3x-1) = 150

2. Are you sure this isn't supposed to be

$5^{2x} \cdot 5^{3x-1} = 150$?

3. im not sure , my friend ask me this question

4. $5^{2z}= (5^x)^2$ and $5^{3x-1}= \frac{(5^x)^3}{5}$

Your equation is $(5^x)^2+ \frac{(5^x)^3}{5}= 150$. If you let $y= 5^x$ you have $y^2+ y^3/5= 150$ or the cubic polynomial $y^3+ 5y^2= 750$. Any rational solution for y must be a factor of 750. I suggest you whack your friend about the ears!