Converting Between Forms of Linear Equations
I can rewrite a linear equation in another form without changing the line.
What students learn
Students learn to rewrite a line in another form by doing the same to every term, then test one point in both forms.
See inside
The key rule
Changing the form never changes the line: do the same to every term, then check one point in both.
y = mx + b ↔ Ax + By = C
Put the same x into both forms: they must give the same y.
Watch out
Write y = (3/4)x − 2 in standard form.
The mistake: 4y = 3x − 2, so 3x − 4y = 2The −2 was not multiplied by 4.
The fix: 4y = 3x − 8, so 3x − 4y = 8Multiply every term by 4.
The mistakes it targets
- Forgets to multiply the constant when clearing a fraction
- Divides only the x term when solving for y
- Moves a term to the other side with the wrong sign
- Leaves the x coefficient negative in standard form
The interactive Teacher Deck (32 slides, PowerPoint)
- The Learn page taught on screen: 8 fill-in blanks, each filled on its own click as students write it
- The worked example one slide per step (four steps), each with the reason for the step
- Six practice and three apply problems: a your-turn slide with a think-time bar, then the solution one line per click
- Jump buttons on every slide: go straight to any problem, the answer bank or the exit ticket
- Speaker notes on each problem: the question to ask, the worked answer and the common error to listen for
- A completed deck PDF (19 pages) with every slide fully built, to print or post
The student packet (9 pages)
- Learn: guided notes with four definitions, the key rule, a worked example and a Watch Out error pair
- Practice: two warm-up, two standard and two stretch problems, with an answer bank for self-checking that hides three common-mistake decoys
- Apply: one word problem, a reasoning prompt and one error analysis
- Assess: an exit ticket of four items, two per page, with an I-can self-rating
- Homework (page 5): eight new problems, two warm-up, four standard and two stretch
- Answer key (pages 6–7): every problem worked step by step, four common mistakes with what to do about each, and a grading guide, plus the homework key (page 8)
- Color and ink-saver editions of the whole packet
Standard codes refer to the Common Core State Standards for Mathematics. Math Class 678 is an independent publisher, not affiliated with, sponsored by, or endorsed by NGA Center or CCSSO. Every product is sold on Teachers Pay Teachers.