We do this:
First multiply the matrices together:
Now set the two matrices equal to each other:
We can write the matrices as a system of equations:
Thus, if we set each equation equal to zero, we have
Now, how do we determine and ?
There are infinitely many solutions.
I'll pick a simple one: and
These two values, and any integer multiple of them will satisfy the equation we came up with.
Does this make sense?