`a. 2^3+ 2.(1/2)^0- 1+ [(-2)^2 : 1/2 )].8`
`=8+2.1-1+[4:1/2].8`
`=8+2-1+8.8`
`=10-1+64`
`=9+64`
`=73`
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`b, 4.(1 1/4)^2 + 2^5 . [(3/4)^2 : (5/4)^3] : (3/2)^2`
`=4.(5/4)^2+32.[9/16:125/64]:9/4`
`=4. 25/16+32. 36/125:9/4`
`=25/4+1152/125:9/4`
`=25/4+512/125`
`=5173/500`
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`c,(5^-5 )^-1 . (1/2)^-2 . 1/105`
`=(1/3125)^-1. 4. 1/105`
`=3125.4. 1/105`
`=12500. 1/105`
`=2500/21`