Need help with an Inverse Variation question?find the missing value (3,7) (x,6) ok I know that I am going to end up with 21=6x but after this I am lost.

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neela's profile pic

neela | High School Teacher | (Level 3) Valedictorian

Posted on

The pair of values u and v inversely varies implies that as u increases v decreases proportionally and vice versa.

It also implies that u is directly proportional to 1/v. Therefore,

u = k(1/v). Here k is called the costant of proportionality and could be found by  putting the values of u and v in the relation, u =k(1/v) from the first pair, i.e., u=3 and v =7. So,

3=k/7 or k = 7*3 = 21

Therefore,  u = (7*3)/v. Using the values of second pair,i.e., substituting u =x and v =6, we get:

x= (7*3)/6 = 21/6 = 7/2 =3.5


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angmerg128's profile pic

angmerg128 | Elementary School Teacher | (Level 1) eNoter

Posted on

This is the formula you need z=k/p

In a formula Z varies inversely as 3.

Find the missing constant by using the first set of data. (3=k/7 so K =21).Because we know that k divided by 7 = 3 and we know that 21 divided by 7 is 3

Now, use the formula and the constant which is k to find the missing value. So you would do Z = k/p.... Z = 21/6... so divide 21 by 6. Therefore your missing value is 3.5

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