Question 1187303
Let {{{f(x)=x^2+6x}}}

Evaluate {{{f(2)}}}=

 {{{f(2)=2^2+6*2}}}

 {{{f(2)=16}}}


Solve {{{f(x)=-9}}}

 {{{-9=x^2+6x}}}

 {{{0=x^2+6x+9}}}

 {{{0=(x + 3)^2}}}

solutions:  {{{x = -3}}} (multiplicity 2, or a double root)