9: \(\left\lbrack5^{30}+4\cdot\left(12-7\right)^{30}\right\rbrack:5^{29}\)
\(=\left\lbrack5^{30}+4\cdot5^{30}\right\rbrack:5^{29}=\frac{5^{31}}{5^{29}}\)
\(=5^2=25\)
10: \(245-\left\lbrack\left(3^2-2^2\right)\cdot10-5\right\rbrack\)
\(=245-\left\lbrack\left(9-4\right)\cdot10-5\right\rbrack\)
=245-(50-5)
=245-45
=200
11: \(25\cdot2^3-\left(9-14\right)+\left(29-34+20\right)\)
\(=25\cdot8-\left(-5\right)+\left(-5+20\right)\)
=200+5-5+20
=200+20
=220
12: \(25+\left(45-126+174\right)-\left(174+145-126\right)\)
=25+45-126+174-174-145+126
=25+45-145
=25-100
=-75
13: \(27:\left\lbrace480:\left\lbrack400-\left(120+24\cdot5\right)\right\rbrack\right\rbrace\)
=27:{480:[400-(120+120)]}
=27:{480:[400-240]}
=27:{480:160}
=27:3
=9
