1) -4 5/7 x 33 1/3 + 4 5/7 x 47 1/3= -33/7x100/3+ 33/7x142/3
= 33/7(-100/3 + 142/3)
= 33/7x 14
= 66
2) (3/5+5 2/3):121/19+(-5 2/3+2/5):121/19= (3/5+5 2/3 - 5 2/3+2/5) : 121/19
= 1: 121/19
= 19/121
3) 1/2+(-1/7)-(-1/13)+-1/3-(-2/5)+-11/21+1/10 .
=1/2 - 1/7 + 1/13 - 1/3 + 2/5 - 11/21 + 1/10
= (1/2+ 1/10+ 2/5) +( -1/7 - 11/21 - 1/3) + 1/13
= 1 -1 + 1/13
= 1/13
4) 3^x+2+3^x=270 (câu này hình như bị sai đề rồi bạn )