150k views
19 votes
Find the value of two numbers if their sum is 12 and their difference is 4. Systems of equations 8th grade math.

Find the value of two numbers if their sum is 12 and their difference is 4. Systems-example-1
User Onur
by
3.9k points

1 Answer

5 votes

To solve this problem, we will setup a system.

We know that two numbers have a sum of 12 and a difference of 4.

So let's call our first number x and our second number y.

So we know that x + y = 12.

We can also say that x - y = 4.

Now rewrite the equations on top of each other.

x + y = 12

x - y = 4

Now we can use addition to solve this system.

When we add the equations together, the y's will cancel.

So we have 2x = 16.

Now divide both sides by 2 and x = 8.

Now plug an 8 back in for x in the first equation to find that y = 4.

So our numbers are 8 and 4.

User Jim Bray
by
3.1k points