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    It looks easy but I can't find the answer .Please help

    a and b are odd numbers

    Give an example to show that the value of 2(a+b) is a multiple of 4.

    thnx
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    An odd number is represented by 2n+1 or 2n+3
    So substitute those into 2(a+b) and factor out 4.

    -edit- Did you mean an example or algebraic proof? Because any example of odd numbers should work.
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    (Original post by alextheowl)
    An odd number is represented by 2n+1 or 2n+3
    So substitute those into 2(a+b) and factor out 4.

    -edit- Did you mean an example or algebraic proof? Because any example of odd numbers should work.
    I need an example of an odd number which can be multiplied by two then added by another odd number to make a multiple of 4
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    (Original post by HARRIS786)
    I need an example of an odd number which can be multiplied by two then added by another odd number to make a multiple of 4
    As I said, you can use any odd numbers. 3 and 5. 11 and 13 - they all work! Maybe you were going wrong with your BIDMAS order? Add inside the brackets first.
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    if you need an example of it working, why not work backwards?

    start with a number that is divisible by 4. take away an odd number and divide that result by 2 to get your starting number
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    Use 1 and -1. Any two odd numbers will work since the sum of any odd numbers is even so we have a multiple of 2 multiplied by another multiple of 2 so it's divisible but by 4.
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    (Original post by alextheowl)
    As I said, you can use any odd numbers. 3 and 5. 11 and 13 - they all work! Maybe you were going wrong with your BIDMAS order? Add inside the brackets first.
    thanks
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    One example is: a=1, b=3.

    Therefore 2(a+b) = 2 (1+3) = 2 x 4 = 8.
    8 is a multiple of four (2 x 4).
 
 
 
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