There were x pens in the cupboard. Paula took out three pens, John took out two pens and Pamela put seven pens back into the cupboard. How would you write the number of pens now in the cupboard?

In Algebra, an expression is one or a number of mathematical symbols that represent a number or quantity.  Expressions can contain any number of numbers, letters and symbols. This quiz also has questions on interpreting expressions; which means applying algebra to real-life situations.