Polynomials first hour

Find the value for a, b and c for  $3\left(ax^2+3x+b\right)=6x^2+cx-12$  

 $\frac{x^3+4x^2+5x+2}{x+2}$  

Find the quotient and remainder for above question.

 $ax^4+2x^3+bx+3$  

The polynomials above leaves a remainder of (15x+9) when divided by  $x^2-x-3$  . Find a and b.

 $2x^3+ax^2-2x+b$  

Given 1 is a zero of the polynomial above when P(x) is divided by x-2,the remainder is -6. Find the value of a and b.