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if 7a+7b=-5 and 3x+2y+9z=-9, what is 56a+10y+45z+15x+56b

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moocow554 | Student, Undergraduate | Valedictorian

Posted July 10, 2013 at 12:52 AM via web

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if 7a+7b=-5 and 3x+2y+9z=-9, what is 56a+10y+45z+15x+56b

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llltkl | College Teacher | Valedictorian

Posted July 10, 2013 at 1:37 AM (Answer #1)

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Given 7a+7b=-5 --- (i)

and   3x+2y+9z=-9 ---- (ii)

The value of 56a+10y+45z+15x+56b has to be determined.

Multiply both sides of eq. (i) with 8 and eq. (ii) with 5 to get,

7a+7b=-5 * 8      `rArr` 56a+56b=-40

3x+2y+9z=-9 * 5 `rArr` 15x+10y+45z=-45

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Now add up both sides of the two equations to get, 56a+56b+15x+10y+45z=-40-45=-85

Upon rearranging, the above equation yields, 56a+10y+45z+15x+56b = -85

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