Question 135651
Only if the function is acutually {{{f(x)=5^x}}}.


If the function is {{{f(x)=5x}}}, then {{{f(-2)=5(-2)=-10}}},


But if {{{f(x)=5^x}}}, then {{{f(-2)=5^(-2)}}}


Remember the rules for exponents:  {{{a^(-n)=1/a^n}}}, so:


{{{f(-2)=5^(-2)=1/5^2=1/25}}}


Hint:  When indicating something should be raised to a power, use the caret mark "^" (shift-6).  x^2 is x squared, 5^x is 5 to the x power.