Question

The sum of 2 numbers is 31 and their difference is 18

Answer 1

The sum of two numbers is 31 and their difference is 18

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 31. In other words, x plus y equals 31 and can be written as equation A:

x + y = 31

The difference between x and y is 17. In other words, x minus y equals 17 and can be written as equation B:

x - y = 18

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

x - y = 18

x = 17 + y

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

x + y = 31

17 + y + y = 31

17 + 2y = 31

2y = 13

y = 6

Now we know y is 6.5 .Which means that we can substitute y for 6.5 in equation A and solve for x:

x + y = 31

x + 6.5 = 31

X = 25.5

Summary: The sum of two numbers is 31 and their difference is 18. What are the two numbers? Answer: 25.5 and 6.5 as proven here:

Sum: 25.5 + 6.5 = 31

Difference: 25.5 - 6.5 = 19

Answer 2

(24.5, 6.5)

Explanation:

We can set up two equations:

x+y=31

x-y=18

Now, when we add the two equations, we get

2x=49

When we divide we get

24.5 for x.

Now we can plug this in the first equation:

24.5+y=31

minus 24.5 on both sides to get

y=6.5

Hope this helped!

~Cain