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Find the direct variation equation

Find the direct variation equation-example-1

2 Answers

7 votes

Answer:

20

Step-by-step explanation:

if y varies directly with x, then it takes the form y=mx

to find m, substitute in the values of x and y to get 35=m*7 and simplify to get that m=5

then the equation becomes y=5x

substitute in the value they gave for x which is 4 to get y=5*4

to get that y=20

User Migle
by
8.6k points
3 votes

Answers:

  • The direct variation equation is y = 5x
  • If x = 4, then y = 20

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Step-by-step explanation:

Let's say that the letter k replaces the green box

We have the equation y = kx

Plug in (x,y) = (7,35) to get the equation 35 = k*7

Dividing both sides by 7 leads to k = 5

Therefore, the direct variation equation is y = 5x

We can check this by plugging in x = 7

y = 5x

y = 5*7

y = 35

So x = 7 leads to y = 35 as expected.

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Do the same for x = 4

y = 5x

y = 5*4

y = 20 when x = 4

Side note: direct variation equations always go through the origin.

User Tim Sands
by
8.6k points

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