Question

X+X+2y+6xyz+3xyz-8xyz

Answer 1

The answer is 2x+2y+xyz

Answer 2

Answer with steps. 

$x+x+2y+6xyz+3xyz-8xyz$
$= (1+1)x+2y+(6+3-8)xyz$
$= 2x+2y+(9-8)xyz$
$= 2x+2y+(1)xyz$
$= 2x+2y+xyz$

Hope this may help you.