The <em><u>correct answer</u></em> is:
15 bicycles and 6 skateboards.
Explanation:
Let x represent the number of bicycles and y represent the number of skateboards. The first equation in our system is then
x+y = 21, since there are 21 total items in the shop.
Each bicycle has 2 tires and each skateboard has 4; this gives us the equation
2x+4y=54 (because they are ordering 54 tires).
This makes our system

We will use elimination to solve this; we first need one of the variables to have the same coefficient in both equations. We will make x the same, and we will do this by multiplying the first equation by 2:

Now we will subtract the second equation from the first one:

Divide both sides by -2:
-2y/-2 = -12/-2
y = 6
There were 6 skateboards. Substituting this into the first equation,
x+6 = 21
Subtract 6 from each side:
x+6-6 = 21-6
x = 15
There were 15 bicycles.
Calculus is a form of math its not a problem so there would be no formula
The answer is .62
When looking at the diagram given the bar for 8 hours is slightly past .6 but not by much. So the answer is .62
Answer:
Franco has 66 baseball cards.
Step-by-step explanation:
This question can be solved by a system of equations.
I am going to say that:
x is the number of baseball cards that Franco has.
y is the number of baseball cards that Juan has.
Franco has 18 fewer baseball cards than Juan.
This means that:

Also:

Together they have 150 baseball cards.
This means that:

Since 




Franco has 66 baseball cards.