Алгебра 8 класс учебник Макарычев, Миндюк ответы – номер 84

а) 1 − a/5 − b/4 = 1 ⋅ 20/1 ⋅ 20 − a ⋅ 4/5 ⋅ 4 − b ⋅ 5/4 ⋅ 5 = 20 − 4a − 5b/20
б) 12 − 1/a − 1/b = 12 ⋅ ab/1 ⋅ ab − 1 ⋅ b/a ⋅ b − 1 ⋅ a/b ⋅ a = 12ab − b − a/ab
в) a − 2/2 − 1 − a − 3/3 = (a − 2) ⋅ 3/2 ⋅ 3 − 1 ⋅ 6/1 ⋅ 6 − (a − 3) ⋅ 2/3 ⋅ 2 = 3a − 6 − 6 − 2a + 6/6 = a − 6/6
г) 4a − a − 1/4 − a + 2/3 = 4a ⋅ 12/1 ⋅ 12 − (a − 1) ⋅ 3/4 ⋅ 3 − (a + 2) ⋅ 4/3 ⋅ 4 = 48 − 3a + 3 − 4a − 8/12 = 41a − 5/12
д) a + b/4 − a + b = a + b/4 − a ⋅ 4/1 ⋅ 4 + b ⋅ 4/1 ⋅ 4 = a + b − 4a + 4b/4 = −3a + 5b/4
е) a + b − a² + b²/a = a ⋅ a/1 ⋅ a + b ⋅ a/1 ⋅ a − a² + b²/a = a² + ab − a² − b²/a = ab − b²/a