Reported speech : transformation et backshift des temps

Transform the following direct speech sentences into reported speech. Pay attention to the backshift of tenses and the change of pronouns and time expressions.

1. Sarah said: 'I am visiting my grandmother in London tomorrow.'
2. Tom told me: 'I have finished my homework, but I forgot my book at school yesterday.'
3. The teacher announced: 'We will organize a trip to the science museum ($Museum_{science}$) next week.'