1.
2,4т = 80%
Х = 100%
Х = (2,4 * 100%) : 80 %
Х = 3 т
2.
2,5т = 100%
Х= 80%
Х = (2,5*80%):100%
Х = 2 т
Ответ: 3т; 2 т
3 8/17+5 2/9*2/5-1 5/17+4 7/9*2/5=6 3/17
1)5 2/9*2/5=94/45=2 4/45
2)4 7/9*2/5=86/45=1 41/45
3)3 8/17+2 4/45=5 428/765
4)5 428/765-1 5/17=4 203/765
5)4 203/765+1 41/45=4 203/765+1 617/765=5 900/765=6 3/17
A)-5ab(3a2-0,2b2+ab)=-15a3b+ab3-5a2b2
б)(a+4)(a-5)=a2-5a+4a-20=a2-a-20
в)