solve the equation by matrix method:-

x+2y-3z=4

2x+4y-5z=12

3x-y+z=3

solve the equation by matrix method:-

x+2y-3z=4

2x+4y-5z=12

3x-y+z=3

Tutors, please sign in to answer this question.

New Wilmington, PA

Write the system first in matrix form:

((1,2,-3),(2,4,-5),(3,-1,1))*(x,y,z)=(4,12,3)

Next, check the determinant of the matrix. If it is zero, the system has no solution (or, if the right side was zero, infinitely many solutions).

In this case, the determinant is non-zero:

det ((1,2,-3),(2,4,-5),(3,-1,1))=7,

which means it the system has a unique solution. You find this solution by computing the inverse of the matrix,

((1,2,-3),(2,4,-5),(3,-1,1))^{-1}=1/7*((-1,1,2),(-17,10,-1),(-14,7,0))

and multiplying it by (4,12,3). You get

(x,y,z) = (2,7,4).

Willowbrook, IL

If you have a system of equations, you can write it in the form:

x=**A**^{-1}**b **where^{
}

So, find the matrix inverse to your matrix, then multiply it by (4, 12, 3) vector and the resulting vector will give you the solution in the form (x,y,z).

I suspect you made a typo in the first equation, so I can't proceed further to illustrate this. Hope you can do it yourself and you know how to invert a matrix.

Rachel K.

Princeton '13 Math & Computer Science Tutor

New York, NY

5.0
(74 ratings)

Daniel B.

Columbia U Math Student

New York, NY

Scott M.

Physics and Math Expert

New York, NY

- Matrix 106
- Finite Mathematics 571
- Matrices 79
- Math Help 5017
- College Help 25
- Augmented Matrix 11
- Math 8993
- Algebra 4708
- Algebra 2 3232