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
Kay [80]
1 year ago
9

The value of y is directly proportional to the value of x.If y=12 when x=9, what is the value of x when y=80

Mathematics
1 answer:
Simora [160]1 year ago
7 0

Step 1:

Write the formula connecting y and x.

\begin{gathered} y\text{ }\propto\text{   x} \\ y\text{ = kx} \\ k\text{ = }\frac{y}{x} \end{gathered}

Step 2:

Find the value of k when y = 12 and x = 9

\begin{gathered} k\text{ = }\frac{y}{x}\text{  =  }\frac{12}{9}\text{   =  }\frac{4}{3} \\ \text{Therefore} \\ y\text{ = }\frac{4}{3}x \end{gathered}

Step 3

You can find x when y = 80.

\begin{gathered} \text{Frpm y = }\frac{4}{3} \\ \text{When y = 80} \\ 80\text{ = }\frac{4x}{3} \\ \text{Cross multiply} \\ 4x\text{ = 80}\times3 \\ 4x\text{ = 240     Divide both sides of the equation by 4} \\ x\text{ = }\frac{240}{4} \\ x\text{ = 60} \end{gathered}

Final answer

x = 60

You might be interested in
Write an equation of the line in either point slope or slope intercept form that passes through the points (3,5) and (2,-2). (Hi
Jobisdone [24]

Answer:

Step-by-step explanation:

slope= y2-y1 / x2-x1

= -2-5 / 2-3

= -7 / -1

= 1

6 0
2 years ago
Math!!! Need help!!!!!!!
iogann1982 [59]
Thats either 7/5 or 1 2/5 but since theres a whole number i think its 1 2/5
3 0
3 years ago
Solve for X. *<br> (1 Point)<br> x + 70<br> 76°<br> 410
Yuki888 [10]

Answer:

x = -7

Step-by-step explanation:

41 + 76 + x + 70 = 180

x + 187 = 180

x = 180 - 187

x = -7

7 0
2 years ago
Read 2 more answers
What is the solution to the equation x+2--Ex-5?
yulyashka [42]
The answer to the equation is X = 7
4 0
3 years ago
Which system of inequalities is represented by the graph?
timofeeve [1]

Answer:

The system of inequalities " x + 2 y ≤ 5 and 3 x + y ≤ 4 " is represented by the graph ⇒ D

Step-by-step explanation:

To find the answer let us find the equation of each line

Blue line:

∵ The line passes through points (5 , 0) and (0 , 2.5)

- Find the slope of the line

∵ m = Δy/Δx

∴ \frac{0-2.5}{5-0}=\frac{-2.5}{5}

∴ m = -0.5

- The form of the equation is y = m x  + b, where b is the

   y-intercept (value y at x = 0)

∵ y = 2.5 at x = 0

∴ b = 2.5

- Write the equation of the line

∴ y = - 0.5 x + 2.5

- Multiply both sides by 2

∴ The equation of the blue line is 2 y = - x + 5

- The shading is under the line and the line is solid, that means

  2 y is less than or equal - x + 5

∴ The inequality of the blue line is 2 y ≤ - x + 5

Red line:

∵ The line passes through points (3 , -5) and (0 , 4)

- Find the slope of the line

∴ m=\frac{-5-4}{3-0}=\frac{-9}{3}

∴ m = -3

∵ y = 4 at x = 0

∴ b = 4

- Write the equation of the line

∴ y =  -3 x + 4

∴ The equation of the red line is y = -3 x + 4

- The shading is below the line and the line is solid, that means

  y is less than or equal -3 x + 4

∴ The inequality of the red line is y ≤ -3 x + 4

Let us find which answer is the same with this system of inequalities

∵ 2 y ≤ - x + 5

- Add x to both sides

∴ x + 2 y ≤ 5 ⇒ same as the first inequality of answer D

∵ y ≤ -3 x + 4

- Add 3 x to both sides

∴ 3 x + y ≤ 4 ⇒ same as the second inequality of answer D

The system of inequalities " x + 2 y ≤ 5 and 3 x + y ≤ 4" is represented by the graph

4 0
3 years ago
Other questions:
  • Whats the value of y <br> 2y + 15 = 4y - 45
    7·2 answers
  • Which expression is equivalent to 1/5m − 20
    11·1 answer
  • What is the mode of this data set<br> 8, 11, 20, 10
    13·1 answer
  • Three years ago, the annual tuition at a university was $2,000. The following year, the tuition was $2,200, and last year, the t
    9·2 answers
  • A gym membership costs $25 to join and $14 each month. Write and use an algebraic expression to find the cost of the gym members
    15·1 answer
  • What is the constant rate of change shown in the graph?
    15·1 answer
  • Is 70thounsand written in standard form or word form?explain
    12·1 answer
  • What is 13x+2-17=11
    12·1 answer
  • Someone, please help me
    6·1 answer
  • PLEASE HELP ME!!! I WILL MARK YOU BRAINLIEST!!!
    9·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!