Answer:
The cooperative has to make 70 shirts per day.
Step-by-step explanation:
Let x shirts be the number of shirts in a day the cooperative has to make to fulfill his plan.
In 8 days, it will make 8x shirts.
Everyday, overfilling the norm by 10 shirts, the cooperative makes x + 10 shirts in a day.
The cooperative fulfilled his plan in 1 day less, so it spent [tex]8-1=7[/tex] days and made [tex]7(x+10)[/tex] shirts.
The number of shirts is the same, so
[tex]8x=7(x+10)\\ \\8x=7x+70\\ \\8x-7x=70\\ \\x=70[/tex]
The cooperative has to make 70 shirts per day.
