Writing Equations

An equation is a mathematical statement that asserts the equality of two expressions, typically containing one or more variables.

To solve an equation means to find the value(s) of the variable(s) that make the equation true.

A variable is a symbol, often represented by a letter, that stands for an unknown value in an equation.

An expression is a combination of numbers, variables, and operations without an equality sign, while an equation includes an equality sign.

This can be represented as $$-6n$$ , where $$n$$ is the variable representing the unknown number.

This means you subtract 19 from the product, represented as $$-6n - 19$$ .

You can write an equation by adding fixed costs to variable costs, e.g., $$0.50x + 20 = total cost$$ .

The first step is to isolate the variable term by subtracting 20 from both sides, resulting in $$0.50x = 15$$ .

Subtract 6 from both sides to get $$5x = 15$$ , then divide both sides by 5 to find $$x = 3$$ .

This translates to $$5x + 6 = 21$$ .