linear algebra 1.1 exercises

1) Definition of a linear equation in n variables

A linear equation in n variables x1,x2,x3...xn has the form
=> a1x1+a2x2+...+anxn = b
The coefficients a1,a2,a3...an are real number, and the constant term b is a real number. The number a1 is leading number, and x1 is leading variable.