Answer :
Let x be the cost of the small sode.
Since the large soda cost is twice the small soda, then together would be:
[tex]\begin{gathered} 2x+x=6 \\ 3x=6 \\ x=\frac{6}{3} \\ x=2 \end{gathered}[/tex]Small soda costs: $2
Then, the large soda would cost: 2*2=$4