if the sum of three consecutive odd numbers is 81 . find the greatest odd number of this series
Answers
Let the first number be x
The 2nd number is x + 2
The 3rd number is x + 4
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Sum of these 3 numbers is 81:
x + ( x + 2) + ( x + 4 ) = 81
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Solve x:
x + ( x + 2) + ( x + 4 ) = 81
x + x + 2 + x + 4 = 81
3x + 6 = 81
3x = 75
x = 25
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Greatest number = x + 4 = 25 + 4 = 29
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Answer: The greatest odd number is 29
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Why do we add 2 to the variable x to get to the next odd number?
x is an odd number. To get to the next odd number, we need to add 2.
Example 1:
If x = 1, adding 2 to x will give us (x + 2) which is (1 + 2) and that will give us 3, which is an odd number.
Example 2:
If x = 21, adding 2 to x will give us (x + 2) which is (21 + 2) and that will give us 23, which is an odd number.
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Why do we not add 1 to the variable x to get to the next odd number?
If x is odd number. If we add 1 to x, we will get (x + 1) which will give us an even number.
Example 1:
If x = 1, adding 1 to x will give us (x + 1) which is (1 + 1) and that will give us 2, which is an even number.
Example 2:
If x = 21, adding 1 to x will give us (x + 1) which is (21 + 1) and that will give us 22, which is an even number.
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29 is greatest integer
x+x+2+x+4=81
3x+6=81