Find the value of two numbers of their sum is 12 and their difference is 4

Question

This question is about systems of equations in word problem format 

Answer 1

Hi Mikalen, the two equations would be:

 

Equation 1: Sum:

 

x + y = 12

 

Equation 2: Difference:

 

x - y = 4

 

Solution:

 

x + y = 12

x  - y =   4

-------------

 

Add the two equations together:

 

2x = 16

 

Divide both sides by 2:

 

x = 8

 

Solve for y:

 

Use equation 1 substituting for x:

 

x + y = 12

 

8 + y = 12

 

Subtract 8 from both sides:

 

y = 4

 

Answer:

 

one number is 8 and the other number is 4.

 

8 + 4 = 12

 

8 - 4  =  4

 

Questions?