Question 10814
let ages be x and y


we then have 
x+y = 26 --eqn1
and
4x-2y = 8 --eqn2


eqn1, scaled up, is: 4x+4y=104


So, we have the following:
4x+4y=104
4x-2y = 8


Now subtract them, to give 6y = 96


--> y = 96/6
so y =16


from eqn1, x+y = 26, so x+16 = 26 --> x = 10


check in eqn2:
4x-2y
4*10 - 2*16
40 - 32
8.. correct


jon.