Question

Tính giá trị biểu thức:

11 x 3^22 x 3^7 - 9^15

A = __________________

(2 x 3^14)^2

Answer 1

\(A=\dfrac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right).2}\)

\(A=\dfrac{11.3^{22+7}-\left(3^2\right)^{15}}{2^2.\left(3^{14}\right)^2}\)

\(A=\dfrac{11.3^{29}-3^{30}}{4.3^{28}}\)

\(A=\dfrac{11.3^{29}-3^{29}.3}{4.3^{28}}\)

\(A=\dfrac{3^{29}.\left(11-3\right)}{3^{28}.4}\)

\(A=\dfrac{3^{28}.3.8}{3^{28}.4}\)

\(A=\dfrac{3^{28}.3.4.2}{3^{28}.4}\)

\(A=6\)

\(A=3.2\)

Vậy : \(A=\dfrac{11.3^{22}.3^7-9^{15}}{\left(2.3^{14}\right)^2}=6\)