Ответ:

  1. \( (0.7)^2=0.49 \).
  2. \( \left(-\frac{1}{3}\right)^4=\frac{1}{81} \).
  3. \( \left(-1\frac{2}{3}\right)^3=\left(-\frac{5}{3}\right)^3=-\frac{125}{27} \).
  4. \( 2^4+5^3=16+125=141 \).
  5. \( (-7)^2-(-2)^2=49-4=45 \).
  6. \( 6\cdot\left(-\frac{5}{6}\right)^2=6\cdot\frac{25}{36}=\frac{25}{6} \).
  7. \( (-0.4)^2-(-0.3)^2=0.16-0.09=0.07 \).
  8. \( (4^4:800+0.4^2):(-0.2)^2=(256:800+0.16):0.04=(0.32+0.16):0.04=12 \).
  9. \( (5.9-6.1)^3\cdot\left(-1\frac{1}{2}\right)^2=(-0.2)^3\cdot2.25=-0.018 \).

Ответ: 1) 0,49; 2) \(\frac{1}{81}\); 3) \(-\frac{125}{27}\); 4) 141; 5) 45; 6) \(\frac{25}{6}\); 7) 0,07; 8) 12; 9) −0,018.