Let x be a number of skateboards and y be the number of bicycles in Eddie's repair shop.
Eddie asks the girls to order 54 new wheels for 21 skateboards and bicycles, then
x+y=21.
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:

From the first equation
Substitute it into the second equation:

Then

Answer: 6 scateboards and 15 bicycles.
Answer:
6 times
Step-by-step explanation:
Let the number of times you visit the pool = x
At a local swim club you can purchase an annual membership for 24 dollars which will allow you 1 dollar admission to the pool all summer.
= $24 + $1× x
= 24 + x
If you do not purchase the membership the pool admission is 5 dollars.
= 5 × x
= 5x
Hence:
24 + x = 5x
Collect like terms
24 = 5x - x
4x = 24
x = 24/4
x = 6 times
The number of times you must visit the pool with a membership that would equal the cost of paying full price is 6 times.
Answer:
See the answers bellow
Step-by-step explanation:
For 51:
Using the definition of funcion, given f(x) we know that different x MUST give us different images. If we have two different values of x that arrive to the same f(x) this is not a function. So, the pair (-4, 1) will lead to something that is not a funcion as this would imply that the image of -4 is 1, it is, f(-4)=1 but as we see in the table f(-4)=2. So, as the same x, -4, gives us tw different images, this is not a function.
For 52:
Here we select the three equations that include a y value that are 1, 3 and 4. The other values do not have a y value, so if we operate we will have the value of x equal to a number but not in relation to y.
For 53:
As he will spend $10 dollars on shipping, so he has $110 for buying bulbs. As every bulb costs $20 and he cannot buy parts of a bulb (this is saying you that the domain is in integers) he will, at maximum, buy 5 bulbs at a cost of $100, with $10 resting. He can not buy 6 bulbs and with this $10 is impossible to buy 0.5 bulbs. So, the domain is in integers from 1 <= n <= 5. Option 4.
For 54:
As the u values are integers from 8 to 12, having only 5 possible values, the domain of the function will also have only five integers values, With this we can eliminate options 1 and 2 as they are in real numbers. Option C is the set of values for u but not the domain of c(u). Finally, we have that 4 is correct, those are the values you have if you replace the integer values from 8 to 12 in c(u). Option 4.