The sum of 2 numbers is 25 and their difference is 7. What are the numbers?

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Answer 1 · 2016-11-17T07:10:48

The numbers are 9 and 16.

It is possible to solve this problem without using algebra and equations.

One number is 7 more than the other, but they add to 25.

If you subtract the difference of 7 first, you will be left with the sum of two equal numbers.

$25 - 7 = 18$ $25-7 = 18$

$18 \div 2 = 9$ $18 div 2 = 9$

The one number is 9 and the other is 7 more than 9, so (9+7 = 16)

The numbers are 9 and 16.

Check: 9+16 = 25#
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You can also use Algebra and only one variable.

Define the numbers first:
Let the smaller number be $x$ $x$
The other number is 7 more than x, so it is $(x + 7)$ $(x+7)$

The sum of the numbers is 25.

$x + x + 7 = 25$ $x+x+7 = 25$

$2 x + 7 = 25 \leftarrow$ $2x +7 = 25" "larr$ subtract 7 from both sides

$2 x = 25 - 7$ $2x = 25-7$

$2 x = 18$ $2x = 18$

$x = 9$ $x = 9" "$ this is the smaller number

The other number is $9 + 7 = 16$ $9+7 = 16$