A number formula_7 is called an opposite number of another number formula_8 if formula_9. By definition, formula_10 is the opposite number of formula_7. For example, formula_12 is the opposite number of formula_13 and vice-versa. This is because formula_14
ʌ WORD_BOUNDARY n ʌ m b ə ɹ WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY s ɛ v ə n WORD_BOUNDARY ɪ z WORD_BOUNDARY k ɔ l d WORD_BOUNDARY ʌ n WORD_BOUNDARY ɑ p ə z ɪ t WORD_BOUNDARY n ʌ m b ə ɹ ɹ WORD_BOUNDARY ʌ v WORD_BOUNDARY ʌ n ʌ ð ə ɹ WORD_BOUNDARY n ʌ m b ə ɹ WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY eɪ t WORD_BOUNDARY ɪ f WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY n aɪ n WORD_BOUNDARY b aɪ WORD_BOUNDARY d ɛ f ɪ n ɪ ʃ ə n WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY t ɛ n WORD_BOUNDARY ɪ z WORD_BOUNDARY ð ɪ WORD_BOUNDARY ɑ p ə z ɪ t WORD_BOUNDARY n ʌ m b ə ɹ ɹ WORD_BOUNDARY ʌ v WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY s ɛ v ə n WORD_BOUNDARY f ɔ ɹ WORD_BOUNDARY ɛ ɡ z æ m p ə l WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY t w ɛ l v WORD_BOUNDARY ɪ z WORD_BOUNDARY ð ɪ WORD_BOUNDARY ɑ p ə z ɪ t WORD_BOUNDARY n ʌ m b ə ɹ ɹ WORD_BOUNDARY ʌ v WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY θ ɜː t iː n WORD_BOUNDARY æ n d WORD_BOUNDARY v aɪ s v ɜː s ə WORD_BOUNDARY ð ɪ s WORD_BOUNDARY ɪ z WORD_BOUNDARY b ɪ k ʌ z WORD_BOUNDARY f ɔ ɹ m j ʊ l ə WORD_BOUNDARY f ɔ ɹ t iː n WORD_BOUNDARY