As with any equation we want to simplify, we always expand brackets first.
#color(red)(2)(color(green)(a+color(red)(3)#)+#color(red)(4)(color(green)(a)color(red)(-2))#
#color(red)(2)xxcolor(green)(a)=color(green)(2a)#
#color(red)(2xx3)=color(red)(6)#
#color(red)(4)xxcolor(green)(a)=color(green)(4a)#
#color(red)(4xx-2)=color(red)(-8)#
Therefore this turns to:
#color(green)(2a+4a)+color(red)(6-8)#
Collecting like terms:
#color(green)(2a+4a=6a)#
#color(red)(6-8=-2)#
This turns to:
#color(green)(6a)color(red)(-2)#
#therefore# The answer is #6a-2#