РЕШЕНИЕ:
S∆ABK + S∆AKM = S∆ / 2 ⇒ S∆ABK = S∆ / 2 – S∆AKM
BK:KM=2:7 ⇒
S∆ABK =
2
S∆AKM
__7
S∆ / 2 – S∆AKM =
2
S∆AKM
__7
7S∆ – 14 S∆AKM = 4 S∆AKM
18 S∆AKM = 7S∆
S∆AKM = 7S∆ / 18
∆AKM ∞ ∆NKB
AM =
KM
BN
__BK
x =
7
BN
__2
BN = 2x / 7
∆ACP ∞ ∆NBP
AC =
PC
BN
__BP
2x__ =
PC
2x / 7
__BP
7 =
PC
1
__BP
S∆ABP =
BP
S∆APC
__PC
S∆ABP =
1
S∆APC
__7
S∆ABP + S∆APC = S∆ ⇒ S∆ABP = S∆ – S∆APC
S∆ – S∆APC =
1
S∆APC
______7
7 S∆ – 7 S∆APC = 1 S∆APC
8 S∆APC = 7 S∆
S∆APC = 7 S∆ / 8
S KPCM = S∆APC – S∆AKM = 7 S∆ / 8 – 7S∆ / 18 =
35S∆ / 72
S∆ABK = S∆/2 – S∆AKM = S∆/2 – 7S∆ / 18 = 2S∆ / 18 = S∆ / 9
S∆ABK / S KPCM = S∆ / 9 : 35S∆ / 72 = 1/9 ∙ 72/35 = 8/35
Ответ: 8/35