Question

Kết quả phép tính \(\dfrac{2^{12}.3^5-4^6.9^2}{\left(2^2.3\right)^6+8^4.3^5}\)-\(\dfrac{5^{10}.7^3-25^5.49^2}{\left(125,7\right)^3+5^9.14^3}\)

Answer 1

Đề đúng: Kết quả phép tính \(\dfrac{2^{12}\times3^5-4^6\times9^2}{\left(2^2\times3\right)^6+8^4\times3^5}-\dfrac{5^{10}\times7^3-25^5\times49^2}{\left(125\times7\right)^3+5^9\times14^3}\) là ...

Giải:

Ta có:

\(\dfrac{2^{12}\times3^5-4^6\times9^2}{\left(2^2\times3\right)^6+8^4\times3^5}-\dfrac{5^{10}\times7^3-25^5\times49^2}{\left(125\times7\right)^3+5^9\times14^3}\) \(=\dfrac{2^{12}\times3^5-\left(2^2\right)^6\times\left(3^2\right)^2}{\left(2^2\right)^6\times3^6+\left(2^3\right)^4\times3^5}-\dfrac{5^{10}\times7^3-\left(5^2\right)^5\times\left(7^2\right)^2}{\left(5^3\times7\right)^3+5^9\times\left(2\times7\right)^3}\) \(=\dfrac{2^{12}\times3^5-2^{12}\times3^4}{2^{12}\times3^6+2^{12}\times3^5}-\dfrac{5^{10}\times7^3-5^{10}\times7^4}{\left(5^3\right)^3\times7^3+5^9\times2^3\times7^3}\) \(=\dfrac{2^{12}\times3^4\times\left(3-1\right)}{2^{12}\times3^5\times\left(3+1\right)}-\dfrac{5^{10}\times7^3\times\left(1-7\right)}{5^9\times7^3+5^9\times2^3\times7^3}\) \(=\dfrac{2^{12}\times3^4\times2}{2^{12}\times3^5\times4}-\dfrac{5^{10}\times7^3\times\left(-6\right)}{5^9\times7^3\times\left(1+2^3\right)}\) \(=\dfrac{2^{13}\times3^4}{2^{12}\times3^5\times2^2}-\dfrac{5^{10}\times7^3\times\left(-6\right)}{5^9\times7^3\times\left(1+8\right)}\) \(=\dfrac{2^{13}\times3^4}{2^{14}\times3^5}-\dfrac{5^{10}\times7^3\times\left(-6\right)}{5^9\times7^3\times9}\) \(=\dfrac{1}{6}-\dfrac{-10}{3}\) \(=\dfrac{7}{2}\)

Vậy kết quả của phép tính đã cho là \(\dfrac{7}{2}\).

Answer 2

\(\dfrac{2^{12}\cdot3^5-4^6\cdot9^2}{\left(2^2\cdot3\right)^6+8^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-25^5\cdot49^2}{\left(125\cdot7\right)^3+5^9\cdot14^3}\)

\(=\dfrac{2^{12}\cdot3^5-\left(2^2\right)^6\cdot\left(3^2\right)^2}{\left(2^2\right)^6\cdot3^6+\left(2^3\right)^4\cdot3^5}-\dfrac{5^{10}\cdot7^3-\left(5^2\right)^5\cdot\left(7^2\right)^2}{\left(5^3\cdot7\right)^3+5^9\cdot\left(2\cdot7\right)^3}\)

\(=\dfrac{2^{12}\cdot3^5-2^{12}\cdot3^4}{2^{12}\cdot3^6+2^{12}\cdot3^5}-\dfrac{5^{10}\cdot7^3-5^{10}\cdot7^4}{5^9\cdot7^3+5^9\cdot2^3\cdot7^3}\)

\(=\dfrac{2^{12}\cdot3^4\left(3-1\right)}{2^{12}\cdot3^5\left(3+1\right)}-\dfrac{5^{10}\cdot7^3\left(1-7\right)}{5^9\cdot7^3\left(1+2^3\right)}\)

\(=\dfrac{2}{3\cdot4}-\dfrac{5\cdot\left(1-7\right)}{1+8}\)\(=\dfrac{1}{3\cdot2}-\dfrac{5\cdot\left(-6\right)}{9}\)

\(=\dfrac{1}{6}-\dfrac{-10}{3}=\dfrac{1}{6}+\dfrac{10}{3}=\dfrac{7}{2}\)

Answer 3

\(\dfrac{7}{2}\)