Equations with Variables on Both Sides, Algebra 1 lesson packet and Teacher Deck (HSA.REI.B.3)
HSA.REI.B.3 Algebra 1 Unit 2: Linear Equations in One Variable

Equations with Variables on Both Sides

I can solve an equation with variables on both sides by collecting the x terms on one side.

What students learn

Students learn to solve equations with x terms on both sides: they remove an x term from one side by doing the same to both sides, then solve what is left and test it in both sides.

See inside

The key rule

Remove the x term from one side by doing the same to both sides. Then solve what is left in reverse order.

5x = 3x + 8 → 2x = 8 → x = 4

Every equation here has different x coefficients on its two sides, so an x term is always left.

Watch out

Solve 6x + 4 = 2x + 24.

The mistake: 8x + 4 = 24, so x = 2.5The 2x was taken off the right but added to the left.

The fix: 4x + 4 = 24, so x = 5Subtract 2x from both sides. Then 4x = 20.

The mistakes it targets

  • Joins x terms across the equal sign
  • Undoes a subtraction by subtracting again
  • Adds a lone variable to the other x term instead of subtracting it
  • Drops a term when simplifying one side
  • Checks the solution in only one side

The interactive Teacher Deck (33 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 (five 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: two word problems 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, five 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.