One scateboard has 4 wheels, then x scateboards have 4x wheels, one bicycle has 2 wheels, then y bicycles have 2y wheels. In total there should be ordered 54 wheels, so

4x+2y=54.

Solve the system of equations:

$\left\{\begin{array}{l}x+y=21\\4x+2y=54.\end{array}\right.$

From the first equation $x=21-y.$ Substitute it into the second equation:

$4(21-y)+2y=54,\\ \\84-4y+2y=54,\\ \\-2y=54-84,\\ \\-2y=-30,\\ \\2y=30,\\ \\y=15.$

Then

$x=21-15=6.$

Answer: 6 scateboards and 15 bicycles.

8 0

2 years ago

You have $7.45. You buy 8 items that cost $0.83 each. How much money do you have left

Agata [3.3K]

Answer:

$0.81

Step-by-step explanation:

left

$7.45-8(0.83)=7.45-6.64=0.81$

I hope I have helped you

6 0

2 years ago

A long-distance athlete can run 1212 kilometer in 3 minutes. How many kilometers can he run in an hour?

Fudgin [204]

He can run 24240 kilometers

4 0

3 years ago

Covert 3.92 into a mixed number in simplest form?

12345 [234]

3.92

= 1.00 + 1.00 + 1.00 + 0.92

= 100/100 + 100/100 + 100/100 + 92/100

= 300/100 + 92/100

= 392/100

-------------------------------------------------------

392/100 = 196/50 = 98/25

3 0

3 years ago

Read 2 more answers