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# What is the value of a if ax + 6y = 18 passes through (2, 1) 2 4 6 8

pqc | Student, Kindergarten | Salutatorian

Posted September 27, 2013 at 6:14 PM via web

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What is the value of a if ax + 6y = 18 passes through (2, 1)

2

4

6

8

Tagged with equation, math

justaguide | College Teacher | (Level 2) Distinguished Educator

Posted September 27, 2013 at 6:16 PM (Answer #1)

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The line represented by the line ax + 6y = 18 passes through the point (2, 1).

Substituting x = 2 and y = 1 in ax + 6y = 18 gives:

a*2 + 6*1 = 18

=> 2a = 18 - 6

=> a = 12/2

=> a = 6

The correct answer is option 3

sciencesolve | Teacher | (Level 3) Educator Emeritus

Posted September 27, 2013 at 6:18 PM (Answer #2)

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You need to replace 2 for x and 1 for y in equation of line `ax + 6y = 18` , such that:

`2a + 6 = 18`

You need to isolate the term that contains a to the left side, such that:

`2a = 18 - 6 => 2a = 12 => a = 6`

Hence, evaluating a, under the given conditions, yields a= 6.

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