Answer:
x = - 4
Explanation:
given
=

since the bases on both sides are equal, both 10 , then equate the exponents , that is
3x = x - 8 ( subtract x from both sides )
2x = - 8 ( divide both sides by 2 )
x = - 4
as a check
substitute x = - 4 into both sides of the equation
left side =
=

right side =
=

both sides are equal , then the solution is x = - 4