\(\left(2x+1\right)^3=729\)
\(\Leftrightarrow\)\(\left(2x+1\right)^3=9^3\)
\(\Leftrightarrow\)\(2x+1=9\)
\(\Leftrightarrow\)\(2x=8\)
\(\Leftrightarrow\)\(x=4\)
Vậy...
\(\left(2x+1\right)^3=729\)
\(\Rightarrow2x+1=9\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=4\)
(2x + 1)3 = 729
(2x + 1)3 = 93
2x + 1 = 9
2x = 9 - 1
x = 8 : 2
x = 4
( 2x + 1 )3 = 729
<=> ( 2x + 1 )3 = 93
<=> 2x + 1 = 9
<=> 2x = 9 -1
<=> 2x = 8
<=> x = 8 : 2
<=> x = 4
\(\left(2x+1\right)^3=729\)
\(\Rightarrow\left(2x+1\right)^3=9^3\)
\(\Rightarrow2x+1=9\)
\(\Rightarrow2x=9-1\)
\(\Rightarrow2x=8\)
\(\Rightarrow x=8:2\)
\(\Rightarrow x=4\)
Vậy x = 4
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