Ответ: -20%.
,,,,,,,
,,,,,,,
(18+x*72/60)+(17-x*90/60)=46,2
18+x*72/60+17-x*90/60=46,2
Х*90/60-х*72/60= 18+17-46 1/5
18/60*х= 34 5/5-46 1/5
3/10*х= -12 4/5
Х= -64/5:3/10
Х= -64/5*10/3
Х= -128/3= -42 2/3
I
- \frac{2}{9*6} = - \frac{1}{9*3} =- \frac{1}{27} ;+ \frac{15}{11*25} = \frac{3}{11*5} = \frac{3}{55} ;
+ \frac{11}{17*1} = \frac{11}{17} ; 1:\frac{9}{101}= - \frac{101}{9} =- 11\frac{2}{9} ;
II
- \frac{6*15}{5*2} =- \frac{3*3}{1} =-9;- \frac{7*21}{9*18} =- \frac{7*7}{3*18} = -\frac{49}{54} ;- \frac{19*9}{3*1}= - \frac{19*3}{1*1}=- \frac{57}{1}=-57 ;
23+21=44 дет за один день
44+44=88 за два
1 кг = 1000г
11 * 1000 = 11000 г