-3a (2 - a) + (3a - 2)² - (3a - 1)² a = ⅓

-3a (2 - a) + (3a - 2)² - (3a - 1)² a = ⅓ -6a+3a²+3a²-2*6a-3a²+6a-1²= =-12a+3a²+1 a = ⅓ -12*⅓+3*⅓²+1= =-4+⅓+1= =5⅓

-3*1/3*(2-1/3)+(3*1/3)²-(3*1/3-1)²= -1*5/3+1-4=5 1/3

-3a+3a²+(3a-2)×(3a-2)-(3a-1)×(3a-1) -3a+3a²+9a²-6a-6a+4-9a²+3a-3a+1 -15a+3a²+5 (-15×⅓)+[3×(⅓)²]+5 -5+(3×¹/₉) +5 =³/₉=⅓