Solve matrix for x and y?

Question

Solve the following matix for x and y:
6 2 times x = -2
-3 1 y 1

I got 10
-7 BUT am not at all confident in the answer. Many thanks!

Answer 1

Sorry, your answer is not right.
We have to solve Ax = B, here
6 2 (x)..........-2
...............=
-3 1 (y)...........1

To solve this problem, let's find the inverse of A
and multiply it by -2
.......................... 1

If we have a 2X2 matrix
a b
c d
There is an easy way to find the inverse(if it exists).
It is

1/(ab -cd) * d -b
..................-c a

provided ab -cd is not 0.
It's easy to remember it in words:
Interchange the elements of the main diagonal
Change the sign of both elements of the other diagonal
Divide the matrix by its determinant, provided
it is not 0. If it is 0, the matrix is not invertible.
Let's carry it out for your problem:
The inverse of A is
1/12 * 1 -2
..........3 6
and, multiplying this by the column vector (-2,1),
we find that
x................. -1/3
..............=
y......................0

PS: Isn't it just awful to try to type this on a standard
keyboard?? Yuck!! Not to mention the fact
that this sender doesn't leave blank space
at the beginning of a line. The dots are here
for the proper spacing.
If you have trouble reading this, just e-mail
me and I'll type it in Word and resend it.
Sorry!!

Answer 2

Regard this as 3 linear equations contained in the unknowns sin(x), cos(y), and tan(z). by Cramer's Rule we come across the answer is sin(x) = a million, cos(y) = -a million, and tan(z) = -a million. From those values all of us comprehend that x = pi/2, y = pi, and z = -pi/4.