значение выражения не зависит от переменной "а"
5
15× --- = 12.5
6
вот, держи
7x+15+15x+8-10=9x
7x+15x-9x=-15-8+10
13x=-13
×=-1
7×-39=2 (×+3)+6-2×+5
7×-39=2×+6+6-2×+5
7×-2×+2×=6+6+5+39
7×=56
×=56÷7
×=8
Ответ:
Пошаговое объяснение:
3 1/5 : 2 2/15 = 16/5 : 32/15 = 16/5 * 15/32 = 1/1 * 3/2 = 3/2
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1 7/8 : 4 1/6 = 15/8 : 25/6 = 15/8 * 6/25 = 3/4 * 3/5 = 9/20
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6 1/2 : 1 6/7 = 13/2 : 13/7 = 13/2 * 7/13 = 7/2 = 3 1/2
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6 2/3 : 2 7/9 = 20/3 : 25/9 = 20/3 * 9/25 = 4/1 * 3/5 = 12/5 = 2 2/5
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5 3/11 : 2 7/11 = 58/11 : 29/11 = 58/11 * 11/29 = 58/29 = 2
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5 1/3 : 3 5/9 = 16/3 : 32/9 = 16/3 * 9/32 = 1/1 * 3/2 = 3/2 = 1 1/2
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5 5/14 : 2 1/7 = 75/14 : 15/7 = 75/14 * 7/15 = 5/2 * 1/1 = 5/2 = 2 1/2
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6 2/5 : 1 7/9 = 32/5 : 16/9 = 32/5 * 9/16 = 2/5 * 9/1 = 18/5 = 3 3/5