Later, René Descartes (17th century) introduced the modern notation (for example, the use of x—see below) and showed that the problems occurring in geometry can be expressed and solved in terms of algebra (Cartesian geometry).
Later, René Descartes (17th century) introduced the contemporary notation (for instance, the use of x—see below) and demonstrated that the difficulties in geometry can be expressed and solved using terms of algebra (Cartesian geometry).