Applications Using Direct Variation

Key Questions

• What are some examples of direct variation in real life?

  Answer:

  Direct variation in real life.

  Explanation:

  1. A car travels `x` hours with a speed of `"60 km/h"` `->` the distance: `y = 60x`

  2. A man buys `x` bricks that cost `$1.50` each `->` the cost: `y = 1.50x`

  3. A tree grows `x` months by `1/2` meters each month `->`
     the growth: `y = 1/2 x`

  Nghi N. · 142 · Jun 14 2015
• How can you use direct variation to solve real life problems?

  A good question

  Suppose we have to pay up the parking bill at a mall

  ON THE BILL BOARD IT SAYS
  |____________|

  |

    FOR A 4  HOUR PARKING   YOU HAVE  TO PAY $3.24
  

  |

    AND UNDER IT A LED SAYS YOU HAVE BEEN HERE FOR (5HRS)
  

  |
  |
  |
  |_________

  now what would you do

  you would use direct variation

  let me make a table

  let x be the cost

  |

  hours parked __ cost

  4                                       |                      $3.24
  

  5 | `x`

  `(3.24* 5)/4 = x`

  solving for `x` you will get `4.05`

  Sidharth · 1 · Jan 8 2015

• What are some examples of direct variation in real life?
• How can you use direct variation to solve real life problems?
• How do you find the direct variation equation if y varies directly as x when `x=4`, `y=48`?
• How do you find the direct variation equation if d varies directly as t when `t=7`, `d=329`?
• What is the constant of proportionality "k" if m is directly proportional to h when `m=461.50`, `h=89.6`?
• How do you find the direct variation equation if z is directly proportional to r when `r=412`, `z=51.5`?
• Wesley earns $6.50 per hour at the bookstore. The total amount of his paycheck varies directly with the number of hours he works. How do you write a direct variation equation for the amount of money y Wesley earns for working x hours?
• The money Sam earns(m) varies directly with the number of hours she baby sits(h). She earns $50 for five hours, how do you write the equation?
• Question #fe135
• Can someone please explain what direct proportion means and give real-life examples?
• The value of y varies directly with x, and y= -8 when x=2. How do you find y when x=3?
• Suppose a varies jointly with `b` and `c` and inversely with `d` and `a = 400` when `b = 16`, `c=5`, and `d = 2`. What's the equation that models the relationship?