giúp mình giải bài này tìm x : 2 mũ x nhân 8 = 128 243 : 3 mũ x =27 22/09/2021 Bởi Amaya giúp mình giải bài này tìm x : 2 mũ x nhân 8 = 128 243 : 3 mũ x =27
\(\begin{array}{l} + )\,\,\,{2^x}.8 = 128\\ \,\,\,\,\,\,\,\,{2^x} = 128:8\\ \,\,\,\,\,\,\,\,{2^x} = 16\\ \,\,\,\,\,\,\,\,{2^x} = {2^4}\\ \,\,\,\,\,\,\,\,x = 4\\ + )\,\,243:\,\,{3^x} = 27\\ \,\,\,\,\,\,\,\,{3^x} = 243:27\\ \,\,\,\,\,\,\,\,{3^x} = 9\\ \,\,\,\,\,\,\,\,{3^x} = {3^2}\\ \,\,\,\,\,\,\,\,x = 3 \end{array}\) Bình luận
\(\begin{array}{l}
+ )\,\,\,{2^x}.8 = 128\\
\,\,\,\,\,\,\,\,{2^x} = 128:8\\
\,\,\,\,\,\,\,\,{2^x} = 16\\
\,\,\,\,\,\,\,\,{2^x} = {2^4}\\
\,\,\,\,\,\,\,\,x = 4\\
+ )\,\,243:\,\,{3^x} = 27\\
\,\,\,\,\,\,\,\,{3^x} = 243:27\\
\,\,\,\,\,\,\,\,{3^x} = 9\\
\,\,\,\,\,\,\,\,{3^x} = {3^2}\\
\,\,\,\,\,\,\,\,x = 3
\end{array}\)
1.2^x . 8=128
2^x=16
2^4=16
⇒x=4
2.243:3^x=27
3^x=9
3^2=9 ⇒x=2