Question

The owner of a bike shop sells unicycles and bicycles and keeps inventory by counting seats and wheels. One day, she counts 21 seats and 30 wheels. Which equation in slope-intercept form shows that x bicycles and y unicycles together have a total of 30 wheels?

Answer 1

U=-2b+30

u+b=21 
in slope intercept form this is 
u=-b+21 

The same thing for wheels is 
2b+u=30 
or 
u=-2b+30