Question

Tìm x; biết: 3^x + 3^x+1 + 3^x+2 + 3^x+3 = 1080

Answer 1

đặt 3^x ra ngoài bạn nhé bàn phím mik hỏng rồi ;-;

Answer 2

$\Rightarrow 3^x(1+3+3^2+3^3)=1080$

$\Rightarrow 3^x.40=1080$

$\Rightarrow 3^x=27=3^3$

$\Rightarrow x=3$

Answer 3

\(3^x+3^{x+1}+3^{x+2}+3^{x+3}=1080\)

\(\Rightarrow3^x+3^x.3^1+3^x.3^2+3^x.3^3=1080\)

\(3^x.\left(1+3+9+27\right)=1080\)

\(3^x.40=1080\)

\(3^x=27\)

\(3^x=3^3\)

Vậy: x = 3