Question

tính giá trị các biểu thức sau với b>0:

a,\(\sqrt{b^{10}}\) ; b,\(\sqrt{64b^6}\) ; c,\(12b^6\sqrt{4b^2}\)

Answer 1

a) \(\sqrt{b^{10}}=\sqrt{\left(b^5\right)^2}=\left|b^5\right|=b^5\)(vì b>0)

b) \(\sqrt{64b^6}=\sqrt{\left(8b^3\right)^2}=\left|8b^3\right|=8b^3\)(vì b>0)

c) \(12b^6\sqrt{4b^2}=12b^6\sqrt{\left(2b\right)^2}=12b^6.\left|2b\right|=12b^6.2b=24b^7\)(vì b>0)

Answer 2

a) \(\sqrt{b^{10}}=\sqrt{\left(b^5\right)^2}=b^5\)

Answer 3

a) \(\sqrt[]{b^{10}}=\sqrt[]{\left(b^5\right)^2}=\left|b^5\right|=b\) \(\left(b>0\right)\)

b) \(\sqrt[]{64b^6}=\sqrt[]{\left(8b^3\right)^2}=\left|8b^3\right|=8b^3\) \(\left(b>0\right)\)

c) \(12b^6\sqrt[]{4b^2}=12b^6\sqrt[]{\left(2b\right)^2}=12b^6\left|2b\right|=12b^62b=24b^7\) \(\left(b>0\right)\)