Question 609683
Let:
x=James's tickets
y=Ashley's tickets
z=Amanda's tickets


Write your equations
x+y+z=340
x+40=y
y+80=z


Now solve your system...
x+40=y
x-y=-40


x+y+z= 340
x-y  =-40
 2y+z= 380
    z= 380-2y


y+80=z
y+80=380-2y
y+2y=380-80
3y=300
 y=100


z=380-2y
z=380-2(100)
z=380-200
z=180


x+40=y
x+40=100
x=60


Check:
x+y+z=340
60+100+180=340


James has 60 tickets.
Ashley has 100 tickets.
Amanda has 180 tickets.