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?

A. y = -2x - 30
B. y = -2x + 30
C. y = 2x + 30
D. y = 2x - 30

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?

 		A.	y = -2x - 30
 		B.	y = -2x + 30
 		C.	y = 2x + 30
 		D.	y = 2x - 30

welshfella · Answer

bicycles (x) have 2 wheels and unicycles (y) have 1 wheel, so

2x + y = 30

y = -2x + 30