2(5-9х)+3*5х=6(5-3х)
10-18х+15х=30-18х
15х=20<span>х=4/3 </span>
Длина равна 9+12=21см.
Периметр Р = 9*2+21*2 = 18+42 = 60 см
√605 = √5 ⋅ 9 ⋅ √5 ⋅ 121 = 3 ⋅ √5 ⋅ 11 ⋅ √5 = 3 ⋅ 5 ⋅ 11 = 165.
Ответ: 165
408
196
---------
2448
3672
408
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79968