Sabck = Sabcd - Sakd
Sabcd = AB^2 = 25 см^2
Sakd = 1/2 * KD * AD = 10 см^2
Sabck = 25 - 10 = 15 см^2
Ответ: 15
1) a³+ 8
2) -2⁴+ х²+ 1
3) k³- 125
4) 27 + m³
5) a^7 - a^6 + a⁴ +1
6) 64-n^6
7) 125 + y^6
8) 512 - z^9