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32 votes
I am a 3 digit positive number. The sum of my digits is 18. My middle digit is the product of -2 and -4. My first digit is 3^2.

User Hiepnd
by
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2 Answers

23 votes
23 votes
Let x be the first digit.
Let y be the second digit.
Let z be the third digit.

x+y+z=18

y= (-2)(-4)
y= 8

x= 3^2
x= 9

Therefore z=1.

The number is
= 100x+10y+z
= 100(9)+10(8)+(1)
= 981
User Daniel Becroft
by
3.3k points
19 votes
19 votes

Hi!

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The first digit of this number is 3², which is 9.

The Number is : 9xx

________

The second digit is: -2·(-4)=8.

The Number is : 98x.

________

The sum of all the digits is 18. This gives us an equation that we can solve in terms of x!


\multimap\sf{9+8+x=18} (x is the digit we are looking for)

Now it takes a little arithmetic to find x :)


\multimap\sf{17+x=18}. Just subtract 17 from both sides to find x!


\multimap\sf{x=1}. And Now, can you see the number!

It's 981, of course :)

Hope this made sense to you!

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\large\it{\overbrace{Calligrxphy}}

User Jokeefe
by
2.6k points