Beyond Rankers Academy
Building Minds, Not Just Rankers
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Beyond Rankers Academy
Building Minds, Not Just Rankers
Main site →
A letter like x can stand in for a number we don't know yet. Once a word phrase becomes an expression, and an equation is balanced correctly, finding that hidden number is simple.
A variable (like x, y or n) stands for a number we don't know yet. An expression turns a word phrase into maths symbols.
| Phrase | Expression |
|---|---|
| 5 more than x | x + 5 |
| 3 less than y | y − 3 |
| twice a number n | 2n |
| a number x divided by 4 | x ÷ 4 |
An equation is a balance. Do the OPPOSITE operation to both sides to get the variable alone.
🔑 Opposite operations
To undo + 5, subtract 5 from both sides. To undo × 3, divide both sides by 3. Whatever you do to one side, do to the other.
Undo addition or subtraction FIRST, then undo multiplication or division.
12 IMO-style questions on expressions and equations. 🍀