It's pretty simple! So it looks like you are learning proportions. You would cross multiply to achieve your answer.
First, let's do your first problem:
2 12
--- = ----
5 n
You would take 5 and multiply it by 12 and get 60! Then you would do the same with 2 times n, giving you 2n (because you do not know what n represents YET.)
Now you should have this:
60=2n OR 2n=60
We must isolate our variable, in order to do that, get rid of two! But how? You would do this by dividing 2n by 2. Yet in equations, when you do something to one side, you must do it to the other because they must be EQUAL! (hence the "equa-" in equation)
2n=60
--- ---
2 2 DIVIDE 2 into 60
----------
n= 30 Simplify!
Your final answer for the first question is n= 30!
Answer:
Rita paid 47,500 dollars for the purchase price.
Step-by-step explanation:
We are given the sales tax on a new car is directly proportional to the purchase price of the car which means there is is something k such that
when you multiply it to the sales tax you get the purchase price.
Let's set this equation:
y=kx
Let y represent the purchase price and x the sales tax.
The second sentence tells us that (x,y)=(1500,30000).
We can plug this into y=kx to find the constant k. (Constant means it stays the same no matter what the input and output is).
So we have:
30000=k(1500)
300 =k(15) I went ahead and divided previous equation by 100.
Now divide both sides by 15:
300/15=k
Simplify:
20=k
So the equation to use the answer the question is
y=20x
where y is purchase price and x is sales tax.
So we want to know the purchase price on a car if the sales tax is 2375.
So replace x with 2375:
y=20(2375)
y=47500
Answer:
$14.8
Step-by-step explanation:
There is a mistype in the question. It should say: ... <em>si cada uno de ellos hicieron una contribución de </em><em>dieciseis</em><em> pesos...</em>
So if everybody contributes $14, they make a total of 14*x, where x denotes the number of students. In this scenario, $4 are left, calling y to the cost of the trip, then:
14*x = y - 4 (eq. 1)
In the other scenario, everybody contributes $16 and $6 are in excess, so
16*x = y + 6 (eq. 2)
subtracting eq. 1 to eq. 2:
16*x - 14*x = y + 6 - (y - 4)
2*x = y + 6 - y + 4
2*x = 10
x = 10/2 = 5
Replacing this value in eq. 1:
14*5 = y - 4
70 + 4 = y
y = $74
If every student pays: 74/5 = $14.8, then they would get altogether the exact cost of the trip
You would find the sign if the signs are not the same if you are dividing or multiplying its negitve if its the same its positive
7+9=16 you can use that cause that is the opposite equation
