Explanation:
The general quadratic equation is given below as
[tex]ax^2+bx+c=0[/tex]The equation given in the question is given below as
[tex]3x^2+6x=12[/tex]By reaaranging the equation into the standard form, we will have
[tex]3x^2+6x-12=0[/tex]Hence,
The value of c is
[tex]c=-12[/tex]