Ana was y years old 7 years ago. Represent her age twenty years from now
twenty years from now, means we add 7 years to get to now and another 20 years to get to twenty years from now:
y + 7 + 20
y + 27
twenty years from now, means we add 7 years to get to now and another 20 years to get to twenty years from now:
y + 7 + 20
y + 27