# "We are given to solve:" #
# \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad 3 "*" x = 4. #
# :. "by definition of the operation * :" \qquad \quad 2 ( 3 + x ) +2 (3) = 4. #
# :. \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \ 6 + 2 x + 6 = 4 #
# :. \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \ \
\ \ 2 x + 12 = 4 #
# :. \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \ \ 2 x = -8 #
# :. \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \qquad \ \ \ x = -4. #
# "This is our solution." #