First, subtract #color(red)(21)# from each side of the equation to isolate the term with parenthesis while keeping the equation balanced:
#7(1 - x) + 21 - color(red)(21) = 14 - color(red)(21)#
#7(1 - x) + 0 = -7#
#7(1 - x) = -7#
Next, divide each side of the equation by #color(red)(7)# to eliminate the need for parenthesis while keeping the equation balanced:
#(7(1 - x))/color(red)(7) = -7/color(red)(7)#
#(color(red)(cancel(color(black)(7)))(1 - x))/cancel(color(red)(7)) = -1#
#1 - x = -1#
Then, subtract #color(red)(1)# from each side of the equation to isolate the #x# term while keeping the equation balanced:
#-color(red)(1) + 1 - x = -color(red)(1) - 1#
#0 - x = -2#
#-x = -2#
Now, multiply each side of the equation by #color(red)(-1)# to solve for #x# while keeping the equation balanced:
#color(red)(-1) xx -x = color(red)(-1) xx -2#
#x = 2#
