Answer:
First, identify your variables:
Let x = number of men in attendance.
Let y = number of women in attendance.
x + y = 48.
and
y = 12 + x
sub the second equation in for y in the first equation:
x + (12 + x ) = 48.
12 + 2 x = 48
2 x = 36
x = 18
y = 12 + 18
y = 30