Answer:
Because they both equal d, you can set them equal to each other:
[tex]941-12t=523+26t\\418 = 38t\\t = 11[/tex]
Substitute t = 11 into the equation 523 + 26t = d:
[tex]523 + 26 *11 = d\\523 + 286 = d\\809 = d[/tex]
There will be 809 DVDs and Blu-ray discs sold per month in 11 months.
