Question

Tìm x: 

42 - 2 . ( 32 - 2^{x +1}) = 10

Answer 1

\(42-2\left(32-2^{x+1}\right)=10\)

\(\Leftrightarrow2^{x+1}=16\)

\(\Leftrightarrow2^{x+1}=2^4\)

=> x = 4

Answer 2

\(42-2.\left(32-2^{x+1}\right)=10\)

\(2.\left(32-2^{x+1}\right)=42-10\)

\(2.\left(32-2^{x+1}\right)=32\)

\(32-2^{x+1}=32:2\)

\(32-2^{x+1}=16\)

\(2^{x+1}=32-16\)

\(2^{x+1}=16\)

\(2^{x+1}=2^4\)

\(x+1=4\)

\(x=4-1\)

\(x=3\)

Answer 3

Làm lại :< 

\(42-2\left(32-2^{x+1}\right)=10\)

\(\Leftrightarrow2^{x+1}=16\)

\(\Leftrightarrow x^{x+1}=2^4\)

\(\Leftrightarrow x=4-1\)

<=> x = 3