All straight line graphs have an equation that can be written in the form 𝑦 equals 𝑚𝑥 add 𝑐, where 𝑚, the coefficient of the 𝑥 term, is the gradient or slope of the line. The constant, 𝑐, is ...

For electricity to flow, everything needs to be connected in a big ring. It’s called a circuit. For example, the lights in most houses and flats are part of a circuit controlled by the consumer unit, ...