Algebra: Fixing Common Mistakes
Spot the hidden structural traps in algebra before they derail your solutions. Master the logic behind negative signs, rational cancellations, and equation balancing so your math stays bulletproof.
Like Duolingo, but for Algebra: Fixing Common Mistakes. Tomo turns the whole topic into a game you play five minutes a day, until it actually sticks.
A short one: 11 levels across 2 sections, about 22 minutes end to end, roughly 4 days at five minutes a day. It moves through Spotting Expression Pitfalls and Solving Without Breaking the Rules. It assumes you already know the basics.
Free forever · No credit card · iPhone & Android
Key ideas in Algebra: Fixing Common Mistakes
- A leading minus is equivalent to multiplying every term inside by -1.
- Multiplying a negative term by -1 inverts subtraction into addition.
- Leaving interior signs unchanged is the most frequent distribution trap.
- Subtracting grouped terms requires inverting the sign of each grouped item.
- Subtracting an interior negative produces an added positive term.
- Constant terms outside parentheses combine only after complete sign flips.
- Exponents bind tighter than negation, squaring x before applying the minus.
- Enclosing the negative inside parentheses squares the entire negative value.
- The expression -x² will always evaluate to a non-positive number for real x.
- Innermost grouping symbols must be cleared before tackling outer brackets.
- Clearing inner parentheses flips interior signs before outer signs apply.
- Combining intermediate constants inside brackets reduces sign errors.
- Cancelling represents division and only applies across factors multiplied together.
- Terms connected by addition or subtraction must stay bound to their whole group.
- Dividing only one term in a sum alters the mathematical value of the expression.
- A common factor must be pulled out of every term in the numerator before dividing.
You've tried the other tabs
Thirty open tabs. Four facts you actually kept.
You watched. You nodded. By Sunday it was gone.
One answer, then back to scrolling.
Eight weeks. You meant to finish. You didn't.
Tomo gives Algebra: Fixing Common Mistakes the Duolingo treatment: levels, streaks, and quick quizzes that test what you just learned. That game loop is what the tabs above never had, so it's the one you actually finish.
Here's what playing it feels like
A real question from this course. Take your best guess.
Picture this: you multiply -(4 - 3x). What happens to the subtraction in front of 3x?
Get it right to open this lesson and 10 more in the app.
Where Algebra: Fixing Common Mistakes takes you
- 1
Spotting Expression Pitfalls
- Neutralizing Sign and Parenthesis Traps
- Simplifying Fractions Without Illegal Cuts
- 2
Solving Without Breaking the Rules
- Preserving Truth Across Both Sides
- Factoring Logic and Quadratic Illusions
2 sections · 4 units · 11 levels. Built to play, not to enroll.
You pick the voice
Algebra: Fixing Common Mistakes is taught in the The Storyteller style: every lesson is a story. Want a different feel? In the app you can spin up the same topic in any of Tomo's teaching styles. Same facts, totally different vibe.
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