I keep getting kicked off of Brainly when other tutors go to try and answer this question.

Answer
(C) 15
Explanation
The given equation that represents the number of bags of sand (x) and bags of mulch (y) that can be bought with $105 is
[tex]3x+7y=105[/tex]If no bags of sand are bought, therefore x = 0
Then the number of bags of mulch that can be bought with $105 will be
[tex]\begin{gathered} 3(0)+7y=105 \\ \\ 0+7y=105 \\ \\ 7y=105 \\ \\ y=\frac{105}{7} \\ \\ y=15 \end{gathered}[/tex]