1b) 27^3 * 3^6 * 81^4=3^9 * 3^6 * 3^8 = 3^23
2a) (2/3)^(-4) * 32 - 0.2^(-3)=(3/2)^4 * 32 - 5^3 = (81*32)/16 -125 = 37
5a) 0.2 * x * y * 4 * y^2 = 0.8 * x * y^3
5b) (3/5 * x * y^3)^2 = 9/25 * x^2 * y^6
5c) 8 * a^3 * b^3 * (-4 * a^2 * b^5) = -32 * a^5 * b^8