Question

найдите значение выражения (3/7-1/4)+(2/3-3/5)+0,5

Answer 1

       1        3        2       4
(3/7 - 1/4) + (2/3 - 3/5) + 0,5 = 313/420
1) 3/7 - 1/4 = 12/28 - 7/28 = 5/28
2) 2/3 - 3/5 = 10/15 - 9/15 = 1/15
3) 5/28 + 1/15 = 75/420 + 28/420 = 103/420
4) 103/420 + 5/10 = 103/420 + 210/420 = 313/420