Answer:
a) 5.85
b) 0.0004
Step-by-step explanation:
[tex]a) \: \: \sqrt{ \frac{ {4.5}^{2} + {10.8}^{2} }{4} } \\ \\ = \sqrt{ \frac{ 20.25 + 116.64 }{4} } \\ \\ = \sqrt{ \frac{136.89}{4} } \\ \\ = \sqrt{34.2225} \\ \\ = 5.85 \\ \\ b) \: \: \frac{1}{(2 \times {10}^{5} ) + (5 \times {10}^{4}) } \\ \\ = \frac{1}{(20\times {10}^{4} ) + (5 \times {10}^{4}) } \\ \\ = \frac{1}{(20 + 5) \times {10}^{4} } \\ \\ = \frac{1}{25 \times {10}^{4} } \\ \\ = 0.04 \times {10}^{ - 4} \\ \\ = 0.0004[/tex]
