c) 2,(6) = 24/9
0,5 = 5/10
0,(4) = 4/9
0,25 = 25/100
(5/1 - 24/9) : [5/10 * 1/3 + 4/9 * 25/100] * 3/4 =
= (45/9 - 24/9) : ( 5/30 + 1/9 ) * 3/4 =
= 21/9 : (45/270 + 9/270) * 3/4 =
= 21/9 * 270/54 * 3/4 =
= 7/9 * 5/1 * 4/1 =
= 140/9
d) 1,3(5) = 122/9
6 7/9 = 61/9
0,1 = 1/10
6 2/3 = 20/3
[ 122/9 * 9/61 - 1/10 ] * 20/3 =
= (2/1 - 1/10) * 20/3 =
= 19/10 * 20/3 =
= 38/3
23
a) (-3/16 - 1/8 * 4/5) * 8/13 =
= ( -3/16 -1/10 ) * 8/13 =
= 4/16 * 8/13 =
= 2/13
b) [( -3/28 + 5/6 - 1/7) * ( -14/1) + 5/9 * 9/1] * 4/5 =
= [( -3/28 + 15/28 - 4/28 ) * ( -14/1) + 5/1] * 4/5 =
= (8/28 * (-14/1) + 5/1) * 4/5 =
= (-8/1 + 5/1) * 4/5 =
= -3/1 * 4/5 =
= -12/5
