Practice questions
Challenge questions
Two variables, negative values, or expressions with powers
Word problems
Real-life formulae — substitute and evaluate
How to evaluate
Replace each variable with its given value, then calculate using BODMAS.
If \(x=3\): \(2x^2-5=2(3)^2-5=2\times9-5=18-5=13\)
Watch out: \(-x^2\) means \(-(x^2)\), not \((-x)^2\). Always square first.