Equations
Solving an equation means finding the number x that makes both sides equal. See every step — and the check that shows the answer is right.
Your numbers
3x + 4 = x + 10
Answer
x
3
How to work it out
- 13x + 4 = x + 10
- 22x + 4 = 10 (subtract 1x from both sides)
- 32x = 10 − 4 = 6 (subtract 4 from both sides)
- 4x = 6 / 2 = 3 (divide both sides by 2)
- 5Test: 13 = 13
The formula
Do the same on both sides
An equation is a balance scale: add, subtract, multiply or divide — but always on both sides.
d = b² − 4ac
The discriminant: d > 0 gives two solutions, d = 0 one, and d < 0 none.
x = (−b ± √d) / (2a)
More: Equations and functions
- Linear functiony = ax + b as a graph and table — or find the line through two points.
- Scale and ratiosFrom drawing to reality, the rule of three and dividing in a ratio.
- Two equations with two unknownsSolve a system of equations step by step and see the intersection on the graph.
- Growth and decayPercentage growth against linear growth — table, graph and doubling time.