1.
[(-2/5)⁹:(-2/5)⁵:(-2/5)²]²:(8/5-2)³:(1-1/2)
(-2/5)⁴:(-10+8/5)³:1/2
(-2/5)⁴:(-2/5)³:1/2
-2/5:1/2
-2/5×2/1
-4/5
