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36 votes
36 votes
HELP ME PLEASE !!!

what is the algebraic rule to this chart?

HELP ME PLEASE !!! what is the algebraic rule to this chart?-example-1
User Rbrtl
by
2.5k points

2 Answers

28 votes
28 votes

Answer:

y = ( 7X ) + 1/2 X

Step-by-step explanation:

15 = (7×2) + 1/2 ×2

User Helmut Granda
by
2.8k points
26 votes
26 votes

Answer: y = 7.5x

This is the same as writing y = (15/2)x but I think decimal form is better to work with here.

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Step-by-step explanation:

Focus on any row where x and y are nonzero.

Divide the y over x values.

  • Row two: y/x = 15/2 = 7.5
  • Row three: y/x = 22.50/3 = 7.5
  • Row four: y/x = 45/6 = 7.5
  • Row five: y/x = 75/10 = 7.5

No matter what row you pick, computing y/x leads to 7.5

Since y/x = 7.5, that rearranges to y = 7.5x after multiplying both sides by x.

This is a direct proportion equation. The constant of proportionality is 7.5, which says that y is 7.5 times that of x.

We don't use the first row x = 0 and y = 0 because dividing by zero is not allowed.

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To check the answer, plug in a value like x = 2 to find that...

y = 7.5x

y = 7.5*2

y = 15

This confirms the row with x = 2 and y = 15. I'll let you check the other rows. This time x = 0 is allowed to be plugged in.

User Zeeshan Shabbir
by
2.8k points
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