(х-216)-408=159
(х-216)=408+159
(х-216)=567
х=567+216
х=783
Проверка
(783-216)-408=159
159=159
49:3=13 50:2=25нок (13+2)
(852-439)/7=59
· ·
852 413 |7__
-439 -35 59
------ ----
413 63
-63
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0
.______.______._______.
3см 3 см 3 см
т.е 9 см
15 1/2 - 2 3/8 - 5 5/6 - 6 3/4 + 10 2/3 - 5 5/8= 15 1/2 - 5 5/6 - (2 3/8 + 5 5/8) - 6
3/4 + 10 2/3 = (15 - 5) + (1/2 - 5/6) - 8 + (10-6) + (2/3 - 3/4) =
10 + (3/6 - 5/6) - 8 +4 + (8/12 - 9/12) = 6 - 2/6 - 1/12 =
6 - 4/12 - 1/12 = 5 + (12/12- 5/12) = 5 7/12