Ответ:

Пошаговое объяснение:

1)  (x-4/15)-3/10 = 7/20;

x-4/15 = 7/20+3/10 =>7/20+6/20 = 13/20 =>

x-4/15 = 13/20;

x=13/20+4/15 => 39/60 + 16/60 = 55/60;

x= 11/12.

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2)  7/8-(x+7/12) = 1/6;

-(x+7/12) = 1/6-7/8 =>4/24 - 21/24 = -17/24=>

x+7/12 = 17/24;

x=17/24 - 7/12 =>17/24-14/24 = 3/24 = 1/8;

x=1/8.

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3)  (x+7/25)+3/20 = 4/5;

x+7/25 = 4/5 - 3/20 => 16/20-3/20 = 13/20 =>

x+7/25 = 13/20;

x=13/20 - 7/25 => 65/100 - 28/100 = 37/100;

x= 0.37.