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. How many of each type of cycle are there?

Choose an equation in slope-intercept form that expresses the fact the number of bicycles plus the number of unicycles is 1.

A. u=-b+21
B. -u=b+21
C. 21/6=u
D. b+u=21
E. b=u+21

Answer 1

Unicycle has 1 seat and 1 wheel.
Bicycle has 1 seat and 2 wheels.
u + b = 21
u + 2 b = 30 ⇒ u = 30 - 2 b
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30 - 2 b + b = 21
30 - b = 21
b = 9, u = 30 - 18 = 12
There are 12 unicycles and 9 bicycles.
An equation in slope-intercept form:
u + b = 21
u = - b + 21
Answer: A ) u = - b + 21