Solve the following systems of equations using Cramer's Rule.?

Question

1. 5x + 7y = -3

2x + 3y = -1

2. 2x + 3y = 7

8x + 12y = 2

3. 2x - y + 3z = 9

x + 2z = 3

3x + 2y + z = 10

4. When solving a system of equations, there are three possible solutions: a unique solution, no solution, or an infinite number of solutions. Use three or more sentences to describe each type of possible solution. For each type of solution, please describe what the graph would look like as well as what the algebraic solution would look like.

5. There are four ways that a system of equations can be solved: graphing, substitution, elimination, or using Cramer’s Rule. Use three or more sentences to describe the process that would be used for solving the system using each of the four methods. You may wish to explain why one method would be better than another for certain problems. Your response should contain a minimum of twelve sentences, three for each method.

(*SHOW THE WORK PLEASE*)

Answer 1

hi ce....

solving these using Cramer's rule is not hard just make the question like this, consider [] is the symbol i use for matrix

[  5    7  ]   [x]    =  [-3]

[  2    3  ]   [y]    =  [-1]

then u find the inverse of the

5  7

2  3 matrix, then

to find  x and y

multiply the inverse  with the -3  -1 matrix

(note :put the inverse matrix on the left.)

sorry couldn't help much because

to write the working on this page is so hard.

any one know what program or widget that can be used?

Answer 2

1, 2, 3) Set up a matrix.  Then find out the coefficient matricies and their determinants.  This page explains Cramer's rule very well:

http://www.purplemath.com/modules/cramer...

4) As for what the graphs look like: a unqiue solution has all the lines or planes sharing one point.  Infinite solutions means that the two lines are the same or that the planes inserect to have at least one line in common.  And with no solutions, the lines are parallel (2D), or the lines/planes are skew or parallel (3D).