**Gabriel Cramer** He was born on July 31, 1704 in Geneva (now Switzerland), and died on January 4, 1752 in Bagnols-sur-Cèze, France. Cramer worked on analysis and determinants. He became a mathematics teacher in Geneva and wrote in work related to physics, also in geometry and history of mathematics. Cramer is best known for his work on determinants (1750) but also made contributions to the study of algebraic curves (1750).

## Cramer's Rule

**THE** Cramer's rule is a method of solving simultaneous LINEAR EQUATIONS by the use of DETERMINANTS. A linear equation is an equation that can be represented by a straight line. If two lines intersect, their intersection point is common. The coordinates of this point are said to satisfy both equations "simultaneously". Cramer's rule uses determinants to find the coordinates of the intersection point. Each denominator consists of the coefficients of x and y. The numerator for x is determined by substituting the coefficients of x for the constants on the right side of the equations. The numerator for y is similarly determined. Numerators and denominators are achieved by cross multiplication and subtraction. The method holds for n linear equations with n unknown. In these cases, third-order or higher determinants should be used.