Question

\(\left(-2\right)^x=4^5.16^2\)

Tìm x biết

Answer 1

* Trả lời:

\(\left(-2\right)^x=4^5.16^2\)

\(\Leftrightarrow\left(-2\right)^x=\left(2^2\right)^5.\left(2^4\right)^2\)

\(\Leftrightarrow\left(-2\right)^x=2^{10}.2^8\)

\(\Leftrightarrow\left(-2\right)^x=2^{18}\)

\(\Leftrightarrow\left(-2\right)^x=\left(-2\right)^{18}\) ( \(\left(-2\right)^{18}=2^{18}\))

\(\Rightarrow x=18\)

Answer 2

(-2)^x = 4^5 . 16^2

=> (-2)^x = 4^5 . 4^4

=>(-2)^x = 4^9

=>(-2)^x = 2^18

<=> x = 18

Vậy x = 18