7,5
Объяснение:
S(ABC) = S(AMPT)- (S(AMB)+S(BPC)+S(ACT))
S(AMPT) = 4^2 = 16
S(AMB) = 1*4/2 = 2
S(BPC) = 3*3/2= 4,5
S(ACT) = 1*4/2 = 2
S(ABC) = 16 - (2+4,5+2) = 16 - 8,5 = 7,5
