Solve the following pair of simultaneous equations for x and y.
I don't know why I can't get this one, because it seems pretty simple.
So far I've done this:
I multiplied 1 and 2 and got abx+by=cb
Then I added that and 2 together and got abx+x+2by=cd+d
However the answer in the back of the book is: x=(d-bc)/(1-ab).
I'm just not too sure where I went wrong.