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
mojhsa [17]
3 years ago
8

The value of y varies directly with x, and y=3 when x=9 find y when x = 21

Mathematics
1 answer:
tester [92]3 years ago
3 0

Answer: y = 7

Step-by-step explanation:

Step 1) plug in 3 for y and 9 for x in the direct variation formula, which is y = kx

3 = k(9)

Step 2) Solve for k

3 = k(9) (Divide by 9 on both sides)

3/9 = k (Now simplify 3/9)

1/3 = k. So k = 1/3

*just FYI: “k” is the constant of variation.

Step 3) use the equation y = kx and plug in 1/3 for k

y = 1/3x

Step 4) using the equation y = 1/3x, plug in 21 for x.

y = 1/3(21) (1/3*21 is the same as 21/3)

y = 21/3 (21/3 = 7)

y = 7. So that’s you’re answer! When x=21, y=7 because 7 is 1/3 of 21!

Hope this helps! My best wishes to you as you go through school!

You might be interested in
A company manufactures printers.
Alexus [3.1K]

Answer:

get x isolated

Step-by-step explanation:

8 0
3 years ago
PLZ HELP I PROMISE I WILL GIVE BRAINLIEST!!!! ASAP
irga5000 [103]

Answer:

4c^{7}d^{13}

Step-by-step explanation:

(2cd^{4} )^{2} *(cd)^{5}

4c^{2}d^{8} *c^{5} d^{5}

4c^{7}d^{13}

4 0
3 years ago
What is the first step needed to solve 3 over 4 multiplied by x minus 3 equals negative 18?
NemiM [27]
My answer would be to add 3 to both sides
8 0
3 years ago
In a grid of an auditorium, the vertices of a section of seats are A (40, 20), B (80, 20), C (100, 70),
olganol [36]

Answer:

2500

Step-by-step explanation:

there you go haha

3 0
2 years ago
Which of the following are geometric sequences?<br> Check all that apply.
kolezko [41]

Answers:

<h2>C & D</h2>

Step-by-step explanation:

There are two general types of sequences that follow a pattern, geometric and arithmetic. Let's see the difference between the two:

An arithmetic sequence is produced by adding the same number to all the terms in the sequence.

EXAMPLE:

5, 7, 9, 11, 13, 15, 17 (The number 2 is added to all terms)

To figure out if a sequence is arithmetic, subtract the first term from the second, then the second from the third and so on until you have checked all the terms.

7 - 5 = 2

9 - 7 = 2

11 - 9 = 2

13 - 11 = 2

15 - 13 = 2

17 - 15 = 2

All results equal 2, so the sequence is arithmetic

From your list: The following sequences are arithmetic

A. 5, 10, 15, 20, 25 (common difference of 5)

The next type of sequence is the geometric sequence.

A geometric sequence is produced when the all the terms in the sequence are multiplied or divided by the same number.

EXAMPLE:

100, 50, 25 (Each term is divided by 2)

To figure this out, we divide each term in the sequence by the next term.

100 / 50 = 2

50 / 25 = 2

All results are two, so this sequence can be confirmed to be geometric

From your list: The following sequences are geometric

C. 10, 5, 2.5, 1.25, 0.625, 0.3125 (common quotient of 2)

D. -9, -3, -1, -1/3, -1/9, -1/27 (common quotient of -3)

There is one final type of sequence, which has no common difference, sum, quotient, or product.

EXAMPLE:

5, 6, 8, 9, 11, 12, 14, 15

This sequence has a pattern, the differences between the numbers are not common.

6 - 5 = 1

8 - 6 = 2

9 - 8 = 1

11 - 9 = 2

12 - 11 = 1

14 - 12 = 2

15 - 14 = 1

From your list: The following sequences are neither geometric nor arithmetic

B. 1, 1, 2, 3, 5, 8, 13 (No pattern)

I'n always happy to help :)

6 0
3 years ago
Other questions:
  • How many solutions does the system of two equations shown have? <br> y=3(x+4) <br> y=3(x-4)
    15·1 answer
  • On this assignment, round all answers (when necessary) to exactly three decimal places. The numbers of construction workers for
    8·1 answer
  • 2) if f (2) = 13, which of the following could
    8·1 answer
  • Where are the vertical asymptote(s) f(x) = x2 + 12x + 27/ x2 + 4x + 3 .
    15·1 answer
  • I really need this answer to be right if anyone can help it would be great!!!
    9·2 answers
  • -2 1/3-(-5) can someone help me
    8·1 answer
  • The graph shows the motion of two cars starting at different places on a highway. Their speeds can be compared by comparing the
    12·1 answer
  • A coffee grinder uses a current of 1.20 A and has a resistance of 100 ohms. Calculate the voltage explain
    10·2 answers
  • 10. On the playground, Grace threw the ball 3 more feet than Ella. Grace threw the ball 21
    15·1 answer
  • he two-way table shows the medal count for the top-performing countries in the 2012 Summer Olympics. A 5-column table has 5 rows
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!