No Solution and Infinitely Many Solutions, Algebra 1 lesson packet and Teacher Deck (HSA.REI.B.3)
HSA.REI.B.3 Algebra 1 Unit 2: Linear Equations in One Variable

No Solution and Infinitely Many Solutions

I can tell whether an equation has one solution, no solution, or infinitely many solutions.

What students learn

Students learn to solve an equation and read its ending: x = a number (one solution), a false statement (no solution), or a true statement (all real numbers, infinitely many solutions).

See inside

The key rule

If the x terms drop out, the answer is not a value of x. A false statement left means no solution; a true one means all real numbers.

x + 2 = x + 7 → 2 = 7 → no solution

Reaching 0 = 0 does not mean x = 0: it is true for every x.

Watch out

Solve 2(x + 5) = 2x + 10.

The mistake: 0 = 0, so x = 00 = 0 has no x in it. It does not say what x is.

The fix: 2x + 10 = 2x + 10, all real numbersBoth sides are the same, so every x works. Try x = 1: 12 and 12.

The mistakes it targets

  • Reads 0 = 0 as x = 0
  • Mixes up the no-solution and all-real-numbers endings
  • Joins x terms across the equal sign
  • Undoes a subtraction by subtracting again
  • Picks a missing value that matches the x terms but not the constants

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: 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.