The equation of the line y= 5x+1. Line that is parallel to the function given should have the same slope as the equation which is 5. We use the point-slope form in order to find the second equation that contains the point (4,5).
If there are 70 chairs but only 20 rows then that means he will have to set up 3.5 chairs per row, or Brook could set up 14 rows with 5 chairs in each row.
Srry if that didn't help but that's what i got from that.