Definition:

​Variable: A variable is a placeholder for a number we do not know yet.

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In this lesson, we are going to use variables to hold the place for entire expressions.​

Subject | Subject

Some text here about the topic of discussion

3x - y = 7

2x + y = 8​

How to solve system of equations using substitution:​

Step 1: Solve one of your equations for a certain variable (either x or y it doesn't matter)

Step 2: Substitute the expression you find into your other equation.

Step 3: Combine like terms until you can solve for your remaining variable.

Step 4: Plug the value you find for your variable into your original equation to solve for the final ​variable.

Example:​

x = 8y - 4

x + 8y = 6​

​Example:

​Pedro has 276 more hits than Ricky. Use substitution to solve the system of equations to find how many hits Pedro, p, and Ricky, r, have recorded. The total combined hits is 2,666.

Try it out:​

6x - 2y = -6

11 = y - 5x​

​Step 1: Solve an equation for a variable.

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Step 2: Substitute that variable into your other equation.

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​Step 3: Solve the equation for your variable.

Step 4: Substitute your solution into the original equation.​

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Conclusion: Write two complete sentences about what you learned.​