Question

3^x+1+3^x+2-2x3^x=270 tìm x

Answer 1

3^x+1 + 3^x+2 - 2 x 3^x = 270

3^x ( 3 + 3² - 2) = 270

3^x . 10 = 270

3^x = 270 : 10

3^x = 27

3^x = 3³

x = 3

Answer 2

\(3^{x+1}+3^{x+2}-2.3^x=270\)

\(\Leftrightarrow3.3^x+3^2.3^x-2.3^x=270\)

\(\Leftrightarrow\left(3+3^2-2\right).3^x=270\)

\(\Leftrightarrow10.3^x=270\)

\(\Leftrightarrow3^x=27\)

\(\Leftrightarrow3^x=3^3\)

\(\Leftrightarrow x=3\)