My point is - whoever wrote it - does not have a conceptual feel for math.
It jumps off the page - the first thing they do is start blending info brtween the two equations.
This may work for this simple example - but add another few terms, maybe another variable - etc - and see where you end up -
Also - makes it very hard to check the work. if first equation is modified to Y = mx+b - you can easily check that the answer holds - rather than having to check large multiples etc.
The goal should be to simplify - the test method complicates.
Juhevah stop t'think some of us that READ this TOO don't have a conceptual feel for math?
I sort'a favor gazintah's ....
3 gazintah 9 .. 3