Вычисли а) 3/4-2/7 б) 1/2+3/7 в) 2/9+3/7 г) 8/9-1/2 - вопрос №67078703427123729378912 от Dan363 09.11.2020 22:40

Question

Математика: Вычисли а) 3/4-2/7 б) 1/2+3/7 в) 2/9+3/7 г) 8/9-1/2

Dan363 · Answer

3/4 - 2/7 =(3 × 7 - 2 × 4)/28 = 21/28 - 8/28 = 13/28
1/2 + 3/7 =(1 × 7 + 3 × 2)/14 = 7/14 + 6/14 = 13/14
2/9 + 3/7 =(2 × 7 + 3 × 9)/63 = 14/63 + 27/63 = 41/63
8/9 - 1/2 =(8 × 2 - 1 × 9)/18 = 16/18 - 9/18 = 7/18