Ширина=4см, а P=20см
1)6-2=4см- ширина
2)(6+4)x2=20см-P
p(3a) = 2*(3a)-3 = 6a - 3
3p(a) + 1 + p(3a) = 3(2a-3) + 1 + 6a - 3 = 6a - 9 + 1 + 6a - 3 = 12a - 11
Ответ: 12а - 11
3-2/5*3 1/3=1 2/3<span>
1. 2/5*</span>3 1/3=2/5*10/3=1 1/3
2. 3-1 1/3=2 3/3-1 1/3=1 2/3
ΔABC∞ΔDHF
S(ABC)/S(DHF)=k²
k²=16/25
k=4/5
k=AC/DF
8/DF=4/5
DF=8*5/4=10см
k=BC/HF
4/HF=4/5
HF=4*5/4=5см