Reading & Writing Algebraic Expressions

An algebraic expression is a mathematical phrase that can include numbers, variables, and operation symbols. For example, $$3x + 5$$ is an algebraic expression.

To evaluate an algebraic expression means to substitute the values of the variables and perform the operations to find a numerical value.

A variable is a symbol, usually a letter, that represents an unknown value in an expression or equation. For example, in $$x + 2$$ , $$x$$ is the variable.

A coefficient is a numerical factor in a term of an algebraic expression. For example, in $$4x$$ , 4 is the coefficient.

A constant is a fixed value that does not change. For example, in the expression $$3x + 5$$ , 5 is a constant.

To translate a verbal phrase into an algebraic expression, identify keywords and their corresponding mathematical operations. For example, 'the sum of a number and 8' translates to $$x + 8$$ .

'More than' indicates addition. For example, '5 more than a number' translates to $$x + 5$$ .

'Less than' indicates subtraction. For example, '3 less than a number' translates to $$x - 3$$ .

The algebraic expression is $$\frac{55.16}{g}$$ .

If the daily rental cost is $35 and the mileage charge is $0.10 per mile, the expression for 3 days and m miles is $$3(35) + 0.10m$$ .