Question

Tính giá trị của biểu thức

a) B= \(\left(\dfrac{1}{9}\right)^{2015}\).\(9^{2015}\)-\(96^2\):\(24^2\)

b) C=\(\dfrac{1}{7}\).9.\(\sqrt{49}\)-3.\(\sqrt{\dfrac{16}{9}}\)+\(1^{2017}\)

Answer 1

\(B=\left(\dfrac{1}{9}\right)^{2015}.9^{2015}-96^2:24^2\)

\(=\dfrac{1^{2015}.9^{2015}}{9^{2015}}-\left(2^5.3\right)^2:\left(2^3.3\right)^2\)

\(=1-2^{10}.3^2:2^6.3^2\)

\(=1-\left(2^{10}:2^6\right).\left(3^2.3^2\right)\)

\(=1-2^4.3^4=1-\left(2.3\right)^4\)

\(=1-6^4=1-1296=-1925\)

Answer 2

b: \(C=\dfrac{1}{7}\cdot7\cdot9-3\cdot\dfrac{4}{3}+1=9-4+1=6\)

a: \(=\left(\dfrac{1}{9}\cdot9\right)^{2015}-\left(96:24\right)^2=1-16=-15\)