You can put this solution on YOUR website! lauren is 4 years older than meghan.
L = m + 4
alyssa is 4 years younger than meghan.
a = m - 4
the sum of their ages is 42.
L + m + a = 42
Replace L with (m+4); replace a with (m-4)
(m+4) + m + (m-4) = 42
3m = 42
m = 42/3
m = 14 yrs is Meghan's age
then
14 + 4 = 18 yrs is Lauren's age
and
14 - 4 = 10 yrs is Alyssa's