4x-9y+7x-3y-8x
.......

Answer:
3x-12y
Step-by-step explanation:
4x-9y+7x-3y-8x
group like terms
4x+7x-8x
11x-8x
=3x
-9y-3y
=-12y
combine terms
==3x-12y
Hope this helps! :)