E = D + 24 -> E is Eileen; D is Her Daughter
(E + 8 ) = 2( D + 8 )
(D + 24 + 8) = 2 (D + 8 ) -> substitute E for D + 24
(D + 32) = 2 (D + 8 )
D - 2D = 16 - 32 -> solve for D
- D = -16
D = 16
16 + 24 = E = 40
Eileen is 40; her daughter is 16
Hope this helps!