Математика 5 класс рабочая тетрадь Ткачёва, Виленкин ответы – страница 54

а) 5/16+7/16 =5+7/16=12/16;
б) 12/13+1/13=12+1/13=13/13=1;
в) 47/11-29/11=47-29/11=22/11;
г) 53/61-18/61=53-18/61=36/61.

а) 100/257–(21/257+48/257) =100/257–21+48/257=100/257–69/257=100–69/257=31/257;
б) 200/143–(102/143+26/143) =200/143–102+26/143=200/143–128/143=200–128/143=72/143.

x +5/12=7/12
x =7/12–5/12
x =2/12

x -4/15=16/15
x =16/15+4/15
x =20/15

13/17- x=4/17
x =13/17–4/17
x =9/17

Ответ. а)2/12; б)20/15; в)9/17.