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12+5k=15-4k

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johnjacob87 | eNotes Newbie

Posted October 21, 2013 at 5:10 PM via web

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12+5k=15-4k

3 Answers | Add Yours

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valentin68 | College Teacher | (Level 3) Associate Educator

Posted October 21, 2013 at 5:26 PM (Answer #1)

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`12+5k =15-4k`

`12+5k+4k =15`

`5k+4k =15-12`

`9k =3`

`k=3/9`

`k=1/3`  or equivalent ` k=0.(3)`

First, one needs to have on the left side of the equality the unknown terms and on the right side the known values. Thus we add `+4k` both to the left and to the right of the equality.

Then to have on the right side only known numbers, we add both to the left and to the right of the equality the number `-12` .

Finlay we divide by `9` both sides and simplify both the numerator and the denominator with `3` .

Answer: From the above equality we obtain `k=1/3`

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baxthum8 | High School Teacher | (Level 3) Associate Educator

Posted October 21, 2013 at 10:28 PM (Answer #2)

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`12 + 5k = 15 - 4k`

Add 4k to each side.

`12 + 9k = 15`

Subtract 12 from each side.

`9k = 3`

Divide both sides by 9.

`k = 3/9 = 1/3`

The solution is k = `1/3.`

Check your solution......................

`12 + 5(1/3) = 15 - 4(1/3)`

`12 + 5/3 = 15 - 4/3`

Since 12 = `36/3`  and 15 = `45/3` , we have

`36/3 + 5/3 = 45/3 - 4/3`

`41/3 = 41/3`

The solution works.

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atyourservice | Student , Grade 10 | eNoter

Posted February 28, 2014 at 9:58 PM (Answer #3)

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`12+5k=15-4k`

combine like terms

`5k + 4k = 15 - 12`

`9k = 3 ` divide both sides by 9

`(9k)/9 = 3/9`

`3/9 `  both share a factor of 3 so you can simplify by dividing by 3

`3/ 9 -: 3/3 = 1/3`

the answer is `k=1/3`

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