8x^(3)y^(4)×(−0.5x^(2)y^(5))^(3)×
=8x^3y^4*(-0,5)^3*(x^2)^3*(y^5)^3= =8x^3y^4*(-0,125)*(x^6)*(y^(15))= =8*(-0,125)x^(3+6)*y^(4+15)= =-x^9*y^(19)