if 7m+9 is even, how do i prove m is odd | Mathematics | Page 1

jolly zodiac Oct 24, 2022, 4:59 AM

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can someone help?

crimson garnet Oct 24, 2022, 5:04 AM

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7m+9 = 2k for any natural number k

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isolate to get m

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you can solve this by letting m= 2k and 2k-1

jolly zodiac Oct 24, 2022, 5:10 AM

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i dont understand

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i get the form of odd and even numbers

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but my brains a little slow on understanding how to solve the equation

crimson garnet Oct 24, 2022, 5:15 AM

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when m=2k , 7m+9 = 7(2k)+9 = 14k+9 = 2(7k+4)+1 so it's odd when m is even

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when m=2k-1 , 7m+9 = 7(2k-1)+9 = 14k+2 = 2(7k+1) so it's even when m is odd

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since 7m+9 is even, m has to be odd

jolly zodiac Oct 24, 2022, 5:18 AM

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thank you! this really helped me <3

#if 7m+9 is even, how do i prove m is odd