A = 12 : {390 : [500 - (125 + 35.7)]}
A = 12 : {390 : [500 - (125 + 245)]}
A = 12 : {390 : [500 - 370]}
A = 12 : {390 : 130}
A = 12 : 3 = 4
B = 12000 - (1500 . 2 + 1800.3 + 1800.2 : 3)
B = 12000 - (3000 + 5400 + 1200)
B = 12000 - 9600 = 2400
C = \(\frac{11\cdot3^{22}\cdot3^7-9^{15}}{\left(2\cdot3^{14}\right)^2}=\frac{11\cdot3^{22}\cdot3^7-\left(3^2\right)^{15}}{2^2\cdot3^{28}}=\frac{11\cdot3^{29}-3^{30}}{2^2\cdot3^{28}}=\frac{11\cdot3\cdot3^{28}-3^2\cdot3^{28}}{2^2\cdot3^{28}}\)
\(=\frac{33\cdot3^{28}-9\cdot3^{28}}{4\cdot3^{28}}=\frac{\left(33-9\right)\cdot3^{28}}{4\cdot3^{28}}=\frac{24}{4}=6\)
