The Sum of Two Numbers is 87 and Their Difference is 8

The sum of two numbers is 87 and their difference is 8. What are the two numbers? Let's start by calling the two numbers we are looking for x and y.

The sum of x and y is 87. In other words, x plus y equals 87 and can be written as equation A:

x + y = 87

The difference between x and y is 8. In other words, x minus y equals 8 and can be written as equation B:

x - y = 8

Now solve equation B for x to get the revised equation B:

x - y = 8
x = 8 + y

Then substitute x in equation A from the revised equation B and then solve for y:

x + y = 87
8 + y + y = 87
8 + 2y = 87
2y = 79
y = 39.5

Now we know y is 39.5. Which means that we can substitute y for 39.5 in equation A and solve for x:

x + y = 87
x + 39.5 = 87
X = 47.5

Summary: The sum of two numbers is 87 and their difference is 8. What are the two numbers? Answer: 47.5 and 39.5 as proven here:

Sum: 47.5 + 39.5 = 87
Difference: 47.5 - 39.5 = 8

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The Sum of Two Numbers is 87 and Their Difference is 9
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