The owner of a bike shop sells tricycles (3 wheels) and bicycles (2 wheels), keeping inventory by counting seats and wheels. one day she counts 13 seats and 31 wheels. how many of each type of cycle are there? a. t + b = 13 3t + 2b = 31 b. t + b = 5 3t + 2b = 44 c. t • b = 44 3t + 2b = 13 d. t + b = 31 3t + 2b = 13

A.t + b = 13

3t + 2b = 31

13 is the total made (which counts all tricycles and bicycles)

31 is the total wheels used (so you have to count the amount of wheels used for each bike, and how much of each is made).

hope this helps

step-by-step explanation:

the ratio of red paint to blue paint is always 9/7. that means that, whatever x's value, (4x+12)/(4x-4) has that same ratio. so, set up an equation and cross-multiply to solve for x:

9/7 = (4x+12)/(4x-4)

9(4x-4) = 7(4x+12)

36x - 36 = 28x + 84

8x - 36 = 84

8x = 120

x = 15