Problems are often answered in mathematics by solving equations. We use letters to represent an unknown number or value. To solve an equation, we need to find what number the letter in the equation ...

Simultaneous equations are two linear equations that can be solved using bar models. By remembering that the same letter will always have the same value we can work out the missing values. To solve ...

Most linear algebra courses start by considering how to solve a system of linear equations. \[ \begin{align} a_{0,0}x_0 + a_{0,1}x_0 + \cdots a_{0,n-1}x_0 & = b_0 ...

"Even the +, −, =, and x signs we take for granted only came into widespread use in the 17th century. Which means that the earlier algebraists we know of … all had expressed their equations mostly in ...