Look at this.
It seems that you are correct.
I need to solve using matrices.
I set up the matrix equation
I found the inverse of the first matrix to be (verified with my calculator)
But when multiplying
I get (again verified by my calculator)
But the solution is
Pardon me if I'm doing this completely wrong. I'm doing this work based off a couple instructional internet videos. I've never taken a linear algebra course.
I, on the other hand, would write the "augmented matrix", and row-reduce to
("Cramer's rule" says that the solutions to "Ax= b" are , , and where " " is the matrix A with the first column replace by b, " " is the matrix A with the second column replaced by b, and " " is the matrix A with the third column replaced by b.)
The quickest method for solving a system of equations like this, (meaning the method that requires the fewest arithmetic operations), is simple (Gaussian) elimination.
For this example, subtract the first equation from the second and third to get
Then subtract the first of these from the second to get
That gets you after which back substitution gets you
The other two methods, matrix inversion and Cramer's rule, require far more arithmetic.
please ReneG,how,where did u get all his that u use to express ur self. I mean something like (A)base one,big [ ],dy/dx,B2 etc.am using Samsung GT1500.PLS TELL ME HOW,I WANT ALSO EXPRESS MY THOUGHT CLEARLY.