1) S = a² = 7² = 49 см²;
2) Р = 2 (a + b) = 2 ( 7 + 10) = 2 * 17 = 34 см;
S = a * b = 7 * 10 = 70 см²;
3) P = 2 (a + 3a) = 2 (7 + 3 * 7) = 2 (7 + 21) = 2 * 28 = 56 см;
4) P = 2 (a + a + b) = 2 (7 + 7 + 10) = 2 * 24 = 48 см.
1) 2*2*71/5*3*2равно142/15равно9 7/5
2)90/7*2/25/7/28равно10*1*1/1*25*1равно10/25равно2/5тоесть0,4
812*(54-27+173)=812* 200=162400. Вроде так
...= 15 5/7 - 6 4/7 = 9 1/7