27. Вычисли устно: 3³; −3⁴; 3⁴; −3⁴; (−3)⁴; −3⁴; 1⁸; (−1)⁸; (0,3)²; (0,3)³; (−2/5)²; (1 1/4)²; 20⁴·(1/10)⁴; 10⁸/(2⁶·5⁶); 14⁶/7⁶.

\(3^3=27\); \(-3^4=-81\); \(3^4=81\); \(-3^4=-81\); \((-3)^4=81\); \(-3^4=-81\); \(1^8=1\); \((-1)^8=1\); \((0.3)^2=0.09\); \((0.3)^3=0.027\); \((-\frac25)^2=\frac4{25}\); \((1\frac14)^2=(\frac54)^2=\frac{25}{16}=1\frac9{16}\); \(20^4\cdot(\frac1{10})^4=2^4=16\); \(\frac{10^8}{2^6\cdot5^6}=\frac{(2\cdot5)^8}{2^6\cdot5^6}=2^2\cdot5^2=100\); \(\frac{14^6}{7^6}=2^6=64\).