Question

3) Efetue as multiplicações:
a) 3,2 . 10⁶ × 4, 2 . 10³
b) 1,5 . 10² × 2, 5 . 10⁴

4) Efetue as divisões:


a) 9 . 10⁷ ÷ 3 . 10⁵
b) 4, 5 . 10²⁰ ÷ 3 . 10²⁵




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Answer 1

3.

a)

$3.2 \times {10}^{6} \times 4.2 \times {10}^{3} \\ 3.2 \times 4.2 \times {10}^{6} \times {10}^{3} \\ 13.44 \times {10}^{9} \\ 1.344 \times {10}^{10}$

b)

$1.5 \times {10}^{2} \times 2.5 \times {10}^{4} \\ 1.5 \times 2.5 \times {10}^{2} \times {10}^{4} \\ 3.75 \times {10}^{6}$

4.

a)

$9 \times {10}^{7} \div 3 \times {10}^{5} = \frac{9 \times {10}^{7} }{3 \times {10}^{5} } = \frac{9}{3} \times \frac{ {10}^{7} }{ {10}^{5} } = 3 \times {10}^{2}$

b)

$4.5 \times {10}^{20} \div 3 \times {10}^{25} = \frac{4.5 \times {10}^{20} }{3 \times {10}^{25} } = \frac{4.5}{3} \times \frac{ {10}^{20} }{ {10}^{25} } = 1.5 \times {10}^{ - 5}$