Question

T= (½)-³+(-²/5)-²+(⁴/7)-¹

Answer 1

Saludos  

(a/b)^-n = (b/a)^n       (a/b)^n  = (a^n)/(b^n)

(1/2)^-3 =  (2/1)^3 = 2^3 = 8  

(-2/5)^-2 = (-5/2)^2 = (-5)^2 / (2)^2 = 25/4  

(4/7)^-1 = 7/4   

(1/2)^-3 + (-2/5)^-2 + (4/7)^-1 =

8 + 25/4 + 7/4  = 8 + 32/4 =  8 + 16/2  = 8 + 8 = 16 

R/ 16