First, expand the terms in parenthesis on the right side of the inequality so the common terms can be grouped and combined:
#6x >= 3 + color(red)(4)(2x - 1)#
#6x >= 3 + (color(red)(4) xx 2x) - (color(red)(4) xx 1)#
#6x >= 3 + 8x - 4#
#6x >= -4 + 3 + 8x#
#6x >= -1 + 8x#
Next, subtract #color(red)(8x)# from each side of the inequality to isolate the #x# term while keeping the inequality balanced:
#6x - color(red)(8x) >= -1 + 8x - color(red)(8x)#
#(6 - color(red)(8))x >= -1 + 0#
#-2x >= -1#
Now, divide each side of the inequality by #color(blue)(-2)# to solve for #x# while keeping the inequality balanced. However, because we are multiplying or dividing and inequality by a negative number we must reverse the inequality operator:
#(-2x)/color(blue)(-2) color(red)(<=) (-1)/color(blue)(-2)#
#(color(blue)(cancel(color(black)(-2)))x)/cancel(color(blue)(-2)) color(red)(<=) 1/2#
#x <= 1/2#