câu a
2 mũ x = 512 chia 8
2 mũ x =64
2 mũ x = 2 mũ 6
suy ra x =6
2x.8=512
2x=512:8
2x=64
2x=26
=>x=6
(2x+1)3=729
(2x+1)3=93
2x+1=9
2x=9-1
2x=8
x=8:2
x=4
a) 2x . 8 = 512
2x = 512 : 8
2x = 64
2x = 26
x = 6
b) ( 2x + 1 )3 = 729
( 2x + 1)3 = 93
2x + 1 = 9
2x = 9 - 1
2x = 8
x = 8 : 2
x = 4
a) \(2^x.8=512\)
\(2^x=512:8=64\)
\(\Rightarrow x=6\)
b) \(\left(2x+1\right)^3=729\)
Ta có: \(9^3=729\)
\(\Rightarrow\left(2x+1\right)=9\)
\(2x=9-1=8\)
\(x=8:2=4\)
\(\Rightarrow x=4\)