49. Given the polynomials $A=10 x^{2}-6 x y+3 y^{2}, B=a x^{2}+b x y+c y^{2}, C=15 y^{4}-36 x y^{3}+62 x^{2} y^{2}-$ $20 x^{3} y$. If these three polynomials satisfy $A \times B=C$, then $a=$ $\qquad$ ,$b=$ $\qquad$ , $c=$ . $\qquad$
Reference answer: $0,-2,5$