How to Solve Simultaneous Equations Using Elimination Method

Step-by-Step Guide

1. 1

   Step 1: Write down both of the equations that you'll need to solve.

   3x
   - y = 12 2x + y = 13
2. 2

   Step 2: Number the equations.

   3x
   - y = 12 as number one, and 2x + y = 13 as number two. ,, Remember subtraction can also be referred to as the addition of a negative number.
   
   If the signs are the same, subtract both equations.
   
   If they are different then add the equations. 3x
   - y = 12 + 2x + y = 13
   ------------- 5x = 25 , Divide both sides by the coefficient of the left side.
   
   Take 5 to the other side.It will look like this:x = 25/5. ,, Use the value of x that was obtained above into either equation (but stick with this equation for the time being).
   
   Substitute this value of x into the equation. 3x
   - y = 12 3(5)-y = 12 15
   - y = 12
   - y = 12
   - 15
   - y =
   - 3(divide both sides by negative one, will be able to cut both signs) y = 3 , Substitute both the values into the other equation.
   
   If the two side numbers at the very end equal each other, you've correctly solved this system of simultaneous equations. 3x
   - y = 12 3(5)
   - 3 = 12 15
   - 3 = 12 12 = 12
3. 3

   Step 3: Check if both equations have the same variable/unknown term in them.

4. 4

   Step 4: Look for signs of the unknown variables or terms.

5. 5

   Step 5: Solve to find the first unknown variable from the resulting (rather shortened) equation.

6. 6

   Step 6: 25 divided by 5 makes 5 so we have now found the value of "x" which is 5.

7. 7

   Step 7: Find the value of "y".

8. 8

   Step 8: Check the problem.

Detailed Guide

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