The Sum of Two Numbers is 1 and Their Difference is 8

The sum of two numbers is 1 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 1. In other words, x plus y equals 1 and can be written as equation A:

x + y = 1

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 = 1
8 + y + y = 1
8 + 2y = 1
2y = -7
y = -3.5

Now we know y is -3.5. Which means that we can substitute y for -3.5 in equation A and solve for x:

x + y = 1
x + -3.5 = 1
X = 4.5

Summary: The sum of two numbers is 1 and their difference is 8. What are the two numbers? Answer: 4.5 and -3.5 as proven here:

Sum: 4.5 + -3.5 = 1
Difference: 4.5 - -3.5 = 8

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The Sum of Two Numbers is 1 and Their Difference is 9
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