pleas help me i have to true it in today

Answer:part 6: -4x^3(2x^2 - 9x^2)         =  -4x^3(-7x^2)        = -4*-7 (x^3+2)        = 28 x^5part 7: 5t^-2* 2t^-5          = 5* 2 (t^-2-5)          = 10 t^-7part 8: (3x)^4         = 3*3*3 x^4+4+4        = 27 x^12part 9: (6m^4)^2         = 6*6 m^4+4         = 36 m^8part 10: (x^2)^5 (x^3)^-2           = x^2+2+2+2+2 * 1/x ^3+3           = x^10/x^6          = x^10-6          = x^4part 11: (3b^-2)^2 * (a^2*b^4)^3          = ((3*3)/b^-2-2) * a^2+2+2 * b^4+4+4          = 9/b^-4 * a^6/b^12          = 9 a^6 b^12-4          = 9 a^6 b^8part 12: (2a^2b^5)^-4* (b^-2a^8)^6         = (1/2*2*2*2 a^2+2+2+2 2*2*2*2 b^5+5+5+5) (1/b^2+2+2+2+2+2 * a^8+8+8+8+8+8)       = (1/256 a^8 b^20)(1/b^12 * a^48)      = (1/256 a^48-8 b^-12-20)      = 1/256 a^40 b^-32Part 13: 10^9/10^3       = 10 ^ 9-3      = 10 ^ 6     = 1,000,000Part 14: 4m^10/2m^8      = 4/2 m^10 - 8      = 2 m^2Part 15: y^3z^10/y^5z^9      =  y^3-5 z^10-9     = y^-2 z     = z/y^2Part 16: a^8b^6c^7/a^4b^10c^3         = a^8-4 b^6-10 c^7-3         = a^4 b^-4 c^4          =a^4 c^4/ b^4Part 17: d^2 e^3 f^5/e^6 f^7 g^9         = d^2 e^3-6 f^5-7 g^-9         = d^2 e^-3 f^-2 g^-9         = d^2/e^3 f^2 g^9Part 18: m^-3/3m^-6        = 1/3 (m ^ -3-6)       = 1/3 m^ -9      i hope it will help you!