Đáp án:
\(\begin{array}{l}
a){a^4}\\
b) - {a^3}\\
c)5{a^4}\\
d){a^6}\\
e) - 6{a^6}\\
g)6{a^7}
\end{array}\)
Giải thích các bước giải:
\(\begin{array}{l}
a)\sqrt {{a^8}} = \sqrt {{{\left( {{a^4}} \right)}^2}} = {a^4}\\
b)\sqrt {{a^6}} = \sqrt {{{\left( { - {a^3}} \right)}^2}} = - {a^3}\\
c) - a.\sqrt {25{a^6}} = - a.5.\left( { - {a^3}} \right)\\
= 5{a^4}\\
d)\sqrt {{a^{12}}} = \sqrt {{{\left( {{a^6}} \right)}^2}} = {a^6}\\
e)6a.\sqrt {{{\left( { - {a^5}} \right)}^2}} = 6a.\left( { - {a^5}} \right) = - 6{a^6}\\
g) - \sqrt {36{a^{14}}} = - 6\sqrt {{{\left( { - {a^7}} \right)}^2}} \\
= - 6.\left( { - {a^7}} \right) = 6{a^7}
\end{array}\)
