Answer :
Answer:
Sarah bought 30 pencils
Step-by-step explanation:
1. Let define p, as the number of pencils bought, and m, as the number of markers bought.
2.
[tex]0.15p+0.30m=7.50[/tex]
[tex]p=3m[/tex]
3. Substitute p in the first equation to 3m since p=3m as defined.
[tex]0.15(3m) + 0.30m=7.50\\0.45m+0.30m=7.50\\0.75m=7.50\\m=10[/tex]
plug m into equation p=3m to find the number of pencils bought
[tex]p=3m=3(10)=30[/tex]