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If 5a + 6b = 13 and 4a + 5b = 9, what is the value of 7a + 7b

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ogidi | Student | Honors

Posted December 1, 2012 at 11:18 AM via web

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If 5a + 6b = 13 and 4a + 5b = 9, what is the value of 7a + 7b

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justaguide | College Teacher | (Level 2) Distinguished Educator

Posted December 1, 2012 at 12:28 PM (Answer #1)

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It is given that 5a + 6b = 13 and 4a + 5b = 9

5a + 6b = 13 ...(1)

4a + 5b = 9 ...(2)

(1) - (2)

=> a + b = 4

7*a + 7*b = 7(a +b) = 7*4 = 28

The value of 7a + 7b = 28

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