How do you solve the exponential equation 5^(3x)=25^(x-4)?

1 Answer
Aug 24, 2017

x=-8

Explanation:

As a first approach to solving exponential equations, try to either:

  • make the bases the same
  • make the indices the same.

In this case, notice that 25 is a power of 5," "color(blue)(25 =5^2)

5^(3x) = color(blue)(25)^(x-4)

5^(3x) = color(blue)((5^2))^(x-4)" "larr multiply the indices

color(red)(5)^(3x) = color(red)(5)^(2x-8)" "larr the bases are the same

:. 3x = 2x-8" "larr the indices are equal

3x -2x =-8

x=-8