Math 1 · Unit 6 · Lesson 3 · part 1 of 5
The Words We Use
The vocabulary for this lesson, in one place.
Words we use
| Word | Plain English | What you do |
|---|---|---|
| Elimination (linear combination) | Add or subtract the equations so one variable cancels. | Line them up, make opposite coefficients, add. |
| Opposite coefficients | Numbers like 3 and −3 that add to 0: additive inverses. | The variable's terms add to 0 and it disappears. |
| Multiply an equation | Multiply both sides, every term, by the same number (Unit 1). | To turn coefficients into opposites. |
| Make a zero appear | Adding an opposite gives the additive identity 0 (Unit 1, Lesson 1). | The whole reason elimination works. |
| Back-substitute | Put the number found into either original equation to get the other variable. | Then check the pair in both. |
| Choose the method | Graph to see; substitute when a variable is alone; eliminate when coefficients line up. | All three turn two variables into one. |