The Sum of Two Numbers is 84 and Their Difference is 7

The sum of two numbers is 84 and their difference is 7. 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 84. In other words, x plus y equals 84 and can be written as equation A:

x + y = 84

The difference between x and y is 7. In other words, x minus y equals 7 and can be written as equation B:

x - y = 7

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

x - y = 7
x = 7 + y

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

x + y = 84
7 + y + y = 84
7 + 2y = 84
2y = 77
y = 38.5

Now we know y is 38.5. Which means that we can substitute y for 38.5 in equation A and solve for x:

x + y = 84
x + 38.5 = 84
X = 45.5

Summary: The sum of two numbers is 84 and their difference is 7. What are the two numbers? Answer: 45.5 and 38.5 as proven here:

Sum: 45.5 + 38.5 = 84
Difference: 45.5 - 38.5 = 7

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The Sum of Two Numbers is 84 and Their Difference is 8
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