1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Tanzania [10]
2 years ago
12

How do you find direct variation. I’m having trouble understanding some of these examples.

Mathematics
1 answer:
Rufina [12.5K]2 years ago
5 0
Direct variation is a relation that has the form

y = kx

where k is the constant of proportionality.

If you are told that a relation is a direct proportion, and you are given one data point, you can find k. The you can write the equation of the direct relation.

Here is an example.
The price of gasoline follows a direct variation.
John bought 5 gallons of gas and paid $15.
a) Write an equation for the relation.
b) Using the relation you found, how much do 13.8 gallons cost?

Solution:
Since the relation is a direct variation, it follows the general equation of a direct variation:

y = kx

We are given one data point, 5 gallons cost $15.
We plug in  5 for x and 15 for y and we find k.

y = kx
15 = k * 5
k = 3

Now that we know that k = 3, we rewrite the relation using our value of k.

y = 3x

This is the answer to part a).

Part b)

We use our relation, y = 3x, and we plug in 13.8 into x and find y.

y = 3x

y = 3 * 13.8

y = 41.4

The price of 15 gallons of gas is $41.40.
You might be interested in
show me how to work this problem, point A(7,9)is dilated from the origin by scale factor r was= 6. what are the coordinates of p
frutty [35]

If the point is dilated from the origin by a scale factor of 6

Then the coordinates of point A becomes

A( 6x7 , 6x9)

A_{0,6}(7,9)=(42,\text{ 54)}

6 0
1 year ago
Is this function linear or nonlinear?<br><br> y=2x2−4<br><br> 10 POINTS
mel-nik [20]

Answer:

I think it's nonlinear

6 0
2 years ago
Read 2 more answers
I need help please.
12345 [234]

-3x^2 X=4

4^2= 4x4=

16

16(-3)= -48

5 0
3 years ago
Simplify 4 1/2 x 2 3/5<br> 8 3/7<br> 117/7<br> 8 3/10<br> 11 7/10
Lynna [10]

Answer:

\frac{27}{5}  = 5 \frac{2}{5}

Step-by-step explanation:

4 1/2 × 2 3/5

9/2 × 2 × 3/5

9 × 3/5

<u>=</u><u> </u><u>2</u><u>7</u><u>/</u><u>5</u><u> </u><u>=</u><u> </u><u>5</u><u> </u><u>2</u><u>/</u><u>5</u>

8 0
2 years ago
10 Points! No wrong answers
qwelly [4]

Answer:

420

Step-by-step explanation:

7 * 3 = 21

21 * 2 = 42

42 * 10 = 420

7 * 3 * 2 * 10 = 420

<u>The area is 420</u>

4 0
3 years ago
Other questions:
  • Some one please help!
    12·2 answers
  • Is it possible to draw a rectangle that has an area of 24 square units and a perimeter of 24 units? Explain
    11·1 answer
  • Please help
    10·1 answer
  • Which of the following functions is graphed below?
    5·1 answer
  • FREE BRANLIES IF ANSWER WITH EQUATIONS!! URGENT
    14·2 answers
  • Pls help I’ll brainlest I just need help with part 4
    7·2 answers
  • Simplify: 7^3 x 7^4 please
    11·1 answer
  • Arrange the following set of decimals in descending order
    13·1 answer
  • A lemonade recipe states that 2 cups of sugar are needed for every 3 lemons how many lemons are needed for 6 cups of sugar
    5·1 answer
  • Please help me please.....
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!