First, expand the terms in parenthesis by multiplying each of the terms within the parenthesis by the term outside the parenthesis:
#3g + color(red)(4)(color(blue)(-6) + color(blue)(2g)) = 1 - g#
#3g + (color(red)(4) xx color(blue)(-6)) + (color(red)(4) xx color(blue)(2g)) = 1 - g#
#3g + (-24) + 8g = 1 - g#
#3g - 24 + 8g = 1 - g#
Next, group and combine like terms on the left side of the equation:
#3g + 8g - 24 = 1 - g#
#(3 + 8)g - 24 = 1 - g#
#11g - 24 = 1 - g#
Then, add #color(red)(24)# and #color(blue)(g)# to each side of the equation to isolate the #g# term while keeping the equation balanced:
#11g - 24 + color(red)(24) + color(blue)(g) = 1 - g + color(red)(24) + color(blue)(g)#
#11g + color(blue)(g) - 24 + color(red)(24) = 1 + color(red)(24) - g + color(blue)(g)#
#11g + 1color(blue)(g) - 0 = 25 - 0#
#(11 + 1)color(blue)(g) = 25#
#12g = 25#
Now, divide each side of the equation by #color(red)(12)# to solve for #g# while keeping the equation balanced:
#(12g)/color(red)(12) = 25/color(red)(12)#
#(color(red)(cancel(color(black)(12)))g)/cancel(color(red)(12)) = 25/12#
#g = 25/12#