a family has 3 children the eldest is 8 years older than the middle child and the youngest is 12 years younger than the eldest child of the total of their age is 88 how old is each child?

Answer 1

If their ages are a < b < c then

c = b+8
a = c-12
a+b+c = 88

...

Answer 2

E-8=M
Y+12=E
E+Y+M=88

putting it in standard form..
E-M+0y=8
E-oM-y=12
E+M+Y=88

add the last two
2E+M=100 add to the first equation
3E=108
E=36
M=28
Y=24