1) 20a^3(5a)^2 = 20a^325a^2 = 500a^5.
2) -0.4x^5(2x^3)^4 = -0.4x^516x^12 = -6.4x^17.
3) (-c^3)^212c^6 = c^612c^6 = 12c^12.
1) 20a^3(5a)^2 = 20a^325a^2 = 500a^5.
2) -0.4x^5(2x^3)^4 = -0.4x^516x^12 = -6.4x^17.
3) (-c^3)^212c^6 = c^612c^6 = 12c^12.