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The sum of two numbers is 51, and their difference is 9. What is the value of the smaller number?

User Dstrants
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1 Answer

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Hi there!

We will create a system of equations to find the numbers you are looking for.

Let's say that the x is one number, and the y is the other number, system looks like this:

x + y = 51

x - y = 9

_________ since the y has different sign in both equations, we will add these two equations together and solve it by x, like this:

2x = 60

x = 60/2

x = 30 => x + y = 51

y = 51 - x

y = 51 - 30

y = 21

The value of the smaller number is 21.

Hope this helps!

User Tanay
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