Bài 1:
\(D = {2009^0} = 1\)
Bài 2:
\(\eqalign{A &= {{{{14}^{16}}{{.21}^{32}}{{.35}^{48}}} \over {{{10}^{16}}{{.15}^{32}}{{.7}^{96}}}}\cr& = {{{{\left( {2.7} \right)}^{16}}.{{\left( {3.7} \right)}^{32}}.{{\left( {5.7} \right)}^{48}}} \over {{{\left( {2.5} \right)}^{16}}.{{\left( {3.5} \right)}^{32}}{{.7}^{96}}}}\cr& = {{{2^{16}}{{.7}^{16}}{{.3}^{32}}{{.7}^{32}}{{.5}^{48}}{{.7}^{48}}} \over {{2^{16}}{{.5}^{16}}{{.3}^{32}}{{.5}^{32}}{{.7}^{96}}}} \cr&= {{{2^{16}}{{.5}^{48}}{{.7}^{96}}} \over {{2^{16}}{{.5}^{48}}{{.7}^{96}}}} = 1\cr}\)
Bài 3:
a) \({\left( {2x - 3} \right)^2} = 25\)
\(\Rightarrow 2x - 3 = 5\) hoặc \(2x - 3 = - 5\)
\( \Rightarrow 2x = 8\) hoặc \(2x = - 2\)
\( \Rightarrow x = 4\) hoặc \(x = - 1.\)
b) \({{27} \over {{3^x}}} = 3 \Rightarrow {3^x} = 27:3\)
\(\Rightarrow {3^x} = 9 \Rightarrow {3^x} = {3^2} \)
\(\Rightarrow x = 2.\)
