Algebra – Substitution.
Add the values together to work out the equations.

🙂 = Correct, ☹️ = Incorrect

📌 Rules

• Replace letters with numbers: Substitution means swapping a letter for its given value. For example, if x = 5, the expression x + 4 becomes 5 + 4 = 9.

• Watch out for hidden multiplication: In algebra, a number placed directly next to a letter means they are multiplied together. For example, if n = 4, the expression 3n means 3 × 4 = 12.

💡 Tips

• Use the correct order of operations (BODMAS/BIDMAS): Always perform multiplication or division before addition or subtraction. In the expression 2a + 5 (where a = 3), multiply 2 × 3 = 6 first, then add 5 to get 11.

• Quick typing on our platform: Typing your answer is designed to be super quick and simple! Just type plain digits like 9 or 11 without adding any spaces, words, or equals signs.

⚠️ Warnings

• Do not just stick numbers together: A very common mistake is reading 3n when n = 4 as the number 34. Remember to multiply (3 × 4 = 12) instead!

• Squaring means multiplying by itself: If an expression includes an index like x² and x = 3, you must calculate 3 × 3 = 9, rather than incorrectly multiplying by two (3 × 2 = 6).