An expression is a set of terms combined using the operations +, – , x or \( \div\), for example \(4x − 3\) or \(x^2 – xy + 17\). An equation states that two expressions are equal in value ...

In algebra, letters are used to stand for values that can change (variables) or for values that aren’t known (unknowns). A term is a number or letter on its own, or numbers and letters ...

In addition, gene expression changes can lead to changes in an entire organism, such as molting in insects. In Drosophila, for example, the molting process is regulated by levels of a hormone ...