Your ribbon is 78 inch wide. Your friend's ribbon is 58 inch wide. How much wider is the ribbon you are using?
Algebra?
78 - 58 = ?
56=y
To find out how much wider your ribbon is compared to your friend's ribbon, you need to subtract the width of your friend's ribbon from the width of your ribbon.
Given that your ribbon is 78 inches wide and your friend's ribbon is 58 inches wide, you can subtract 58 from 78 to find the difference:
78 - 58 = 20
Therefore, the ribbon you are using is 20 inches wider than your friend's ribbon.