\(1\dfrac{13}{15}.\left(0,5\right)^2.3+\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\\ =\dfrac{28}{15}.0,25.3+\left(\dfrac{8}{15}-\dfrac{79}{60}\right):\dfrac{47}{24}\\ =\dfrac{7}{15}.3+\dfrac{-47}{60}:\dfrac{47}{24}\\ =\dfrac{7}{5}+\dfrac{-2}{5}\\ =\dfrac{5}{5}=1\)