Question

1) (1×10^5)×(2,7×10^4);
2) (8,2×10^12)÷(2,5×10^7);
3) (5,2×10^-4)×(3,4×10^-3);
4) (4,5×10^-5)÷(9×10^-5);

Answer 1

$1) \: \: \: (1 \times {10}^{5} ) \times (2.7 \times {10}^{4} ) = 2.7 \times {10}^{9} \\ 2) \: \: \: (8.2 \times {10}^{12} ) \div (2.5 \times {10}^{7} ) = \frac{8.2 \times {10}^{12} }{2.5 \times {10}^{7} } = \frac{82}{25} \times {10}^{5} = 3,28 \times {10}^{5} \\ 3) \: \: \: (5.2 \times {10}^{ - 4} ) \times (3.4 \times {10}^{ - 3} ) = \frac{26}{5} \times \frac{17}{5} \times {10}^{ - 7} = \frac{442}{25} \times \frac{1}{ {10}^{7} } = 17.68 \times ( {0.1)}^{7} = 1,768 \times 10 \times ( {10)}^{-7} = 1,768 \times ( {10)}^{-6}$

$4) \: \: \: (4.5 \times {10}^{ - 5} ) \div (9 \times {10}^{ - 5} ) = \frac{45}{90} = \frac{1}{2} = 0.5= 5 \times ( {10)}^{-1}$