Posted by Linda on .
I thought number 4 on this list was incorrect but didn't know how to fully explain it here is the list that I have.
Please look at the following simplification of an algebraic expression. Which line contains the mistake and why?
Line 1: (2x + 6x) + 4y + 3x  2xy
Line 2: (8x) + 4y + 3x  2xy
Line 3: 8x + 3x + 4y  2xy
Line 4: 11x + 4y  2xy
Line 5: 13xy

Algebra 
Steve,
Line 4 is ok: 8x+3x = 11x
Line 5 is bogus. You cannot combine x,y,xy terms.
Line 4 is as far as you can go.