[header] How to use cramer's rule [title] Know the naming convention. [step] In a set of three equations, say 1 , 2 and 3, name the coefficients of the equation 1 as: a1, b1, c1. Name the constant term as d1. 
Similarly, name the coefficients of equations 2 and 3 as: a2, b2, c2 and a3, b3, c3 with their constant terms being d2 and d3 respectively. [title] Arrange the coefficients in a 3x3 matrix named d.