Answer:
[tex]c=1.25b[/tex]
Step-by-step explanation:
If we know that each band costs $1.25, then we know that 2 bands are $2.50, 3 bands are $3.75 etc. The equation above simply states that each band is $1.25, so $1.25 multiplied by the number of bands gives us a total cost. This follows the formula [tex]y=kx[/tex], for a direct proportion equation. Hope this helped :)