Tính: 3 - (- 2/ 7)^9 + (1/ 2)^2 : 2

1.tính
a) 3 -(-2/7)^9 + (1/2)^2 chia 2
b) (5^2) -(-5^2)+ ((-2)^3)^2
C) 2^3 + 3(1/2)^0 - 2^-2 . 4+[(-2)^2 chia 1/2 ] .8 
d) 2^2 - 2^3 +2^4 +2^5 +.........+2^44+2^45