3x-2y=8       x=2y-4   solve for x and y

Expert Answers

An illustration of the letter 'A' in a speech bubbles

The answer here is that x = 6 and y = 5.  Here is how you can find this:

The thing to do here is to take the value that you have been given for x in the second equation and substitute it into the first equation.  So then you have

3 (2y - 4) - 2y = 8

6y - 12 - 2y = 8

4y = 20

y = 5

Now you take this value of y and substitute it back in to the second equation to find x.

x = 2 (5) - 4

x = 10 - 4

x = 6

Approved by eNotes Editorial
An illustration of the letter 'A' in a speech bubbles

3x-2y=8...(1)

 x=2y-4  

Subtract 2y

==> x-2y=-4.....(1)

Subtract (1) from (2)

==> 2x=12 ==> x=6

To calculate y, we will use either equation (1) or (2)

x-2y=-4

Substitute with x=6

==> 6-2y=-4

Subtract 6 from both sides:

==> -2y=-10

Divide by -2:

==> y=5

 

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial