One Variable, One Answer

A linear equation has one variable raised to the first power: 2x + 5 = 13. Solving it means isolating x — peeling away layers until x stands alone. Subtract 5 from both sides: 2x = 8. Divide by 2: x = 4. Every step keeps the equation balanced, like a scale.

The word "linear" comes from "line" — when you graph y = 2x + 5, you get a perfectly straight line. Every point on that line is a pair (x, y) that satisfies the equation. Linear means no curves, no powers, no surprises. This simplicity is why linear equations are the first algebraic tool students learn and the most frequently used in science and business.