3 . 22x + 3 - 4x + 1 = 320
\(\Rightarrow\)3 . 2x + 1 . 2x + 1 . 2 - 4x + 1 = 320
\(\Rightarrow\)6 . 4x + 1 - 4x + 1 = 320
\(\Rightarrow\)5 . 4x + 1 = 320
\(\Rightarrow\)4x + 1 = 64
\(\Rightarrow\)4x + 1 = 43
\(\Rightarrow\)x + 1 = 3
\(\Leftrightarrow\)x = 2