Question

Обчисліть: ( НА ФОТО❗️)

Answer 1

Ответ:

1. $3^{-2} =\frac{1}{3^{2} } =\boxed{\frac{1}{9} }$
2. $(-7)^{-1} =\boxed{-\frac{1}{7} }$
3. $(1\frac{1}{2} )^{-2} =\frac{1}{(1\frac{1}{2} )^{2}} =\frac{1}{(\frac{3}{2} )^{2}}=\frac{1}{\frac{9}{4} } =\boxed{\frac{4}{9} }$
4. $(2,1\times 10^{5} )\times(3\times 10^{-7} )=\\ \\=(2,1\times 3)\times(10^{5} \times10^{-7} )=\\ \\=6,3\times 10^{5-7} =6,3\times10^{-2} =\boxed{0,063}$