\[64;a_{2};a_{3};a_{4};a_{5};a_{6};a_{7} = 46\]
\[a_{7} = a_{1} + 6d\]
\[46 = 64 + 6d\]
\[6d = - 18\]
\[d = - 3.\]
\[a_{2} = 64 - 3 = 61;\]
\[a_{3} = 61 - 3 = 58;\]
\[a_{4} = 58 - 3 = 55;\]
\[a_{5} = 55 - 3 = 52;\]
\[a_{6} = 52 - 3 = 49.\]