write an equation: how many bowls are on display?

[lisaiam]

I need help writing an equation for this question:

Pottery mugs and bowls are on display, 20 pieces in all. There are 4 more mugs than bowls. How many bowls are on display?

 

[skeeter]

Re: write an equation

total number of mugs and bowls is 20 ...
m + b = 20

there are 4 more mugs than bowls ...
could be written m - 4 = b or m = b + 4