I get 32.25 for c), and -2.664 for d). In c) you have wrong exponent: it should be [imath]\left(\frac{1}{5}\right)^{10}[/imath], not [imath]\left(\frac{1}{5}\right)^{10-1}[/imath], but this does not effect the first 3 decimal places. In d) you forgot to factor out get [imath]-\frac{1}{2}[/imath], so you got the answer multiplied by [imath]-2[/imath].