 Simult ax+by=c
 Given the coefficients a, b and c of two linear equations, both in the form ax+by=c, this program will give the point of intersection.    Simult y=mx+c
 Given the coefficients m and c of two linear equations, both in the form y=mx+c, this program will give the point of intersection.    y=mx+c (2pts)
 Given two points in the form (x,y), this program will give the equation of the line passing through them.    y=mx+c (m&1pt)
 Given one point in the form (x,y) and a gradient m, this program will give the equation of the line with that gradient passing through the point.    Perp. bisector
 Given two points in the form (x,y), this program will give the mid-point between them and the equation of the perpendicular bisector.     Simult 3x3
 This program solves 3x3 systems of simultaneous linear equations using a matrix (see also Matrices section).  The RREF function is used for this. (4,2,-3) For example:     x+y=6    2x-z=11    3y+z=3   If there is no solution or infinite solutions to the system then the program reports this.  For example, changing the third equation to 2y+z=3 results in the "Infinite solutions" message shown right, since it then becomes a linear combination of the first two equations.   