(0,0025)-¹×(0,04)½×(½)⁴

(0,0025)-¹ × (0,04)^½ × (½)⁴
=(5².10-⁴)-¹ × (2²×10-²)^½ (½)⁴
= 5-².10⁴ × 2.10-² × 2-⁴
= 5-² × 2-³ × 10²
= (10-²).2-¹.10²
= 2-¹
= ½