139*7=973
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A = (208 - 3*4)/2 = (208 - 12)/2 = 196/2 = 98
b = 112 - 2*4 = 112 - 8 = 104
Площадь каждого пруда
S = a*b = 98*104 = 10192 кв.м.
18+(82-10x):6=100:5,
18+(82-10x):6=20,
(82-10x):6=20-18,
(82-10x):6=2,
82-10x=2*6,
82-10х=12,
10х=82-12,
10х=70,
х=70:10,
х=7.