A) 2 và 1/3 ÷7/9+2/5× 1 và 2/3 -7/3
= 7/3 : 7/9 + 2/5 x 5/3 - 7/3
= 7/3 x 9/7 + 2/5 x 5/3 - 7/3
= 7/3 x ( 9/7 + 2/5 x 5/3 )
= 7/3 x ( 9/7 + 2/3 )
= 7/3 x 41/21= 41/9
B) 25% ×4/5 +3/5 -0.8 +2010
= (1/4 ×4/5 ) + ( 3/5 - 4/5 ) +2010
= 1/5 + -1/5 + 2010
= 0 + 2010
= 2010