First, multiply each side of the equation by #color(blue)(45)color(red)(x)# to eliminate the fraction and isolate the #x# term while keeping the equation balanced. #45x# is the lowest common denominator of the two fractions:
#color(blue)(45)cancel(color(red)(x)) xx 27/color(red)(cancel(color(black)(x))) = cancel(color(blue)(45))color(red)(x) xx 81/color(blue)(cancel(color(black)(45)))#
#1215 = 81x#
Now, divide each side of the equation by #color(red)(81)# to solve for #x# while keeping the equations balanced:
#1215/color(red)(81) = (81x)/color(red)(81)#
#15 = (color(red)(cancel(color(black)(81)))x)/cancel(color(red)(81))#
#15 = x#
#x = 15#