Question

\(\dfrac{5^2.6^9.10+6^5.2^3.15^3}{5^2.6^8.10-2.6^8.10^3}\)

Answer 1

\(=\dfrac{5^2\cdot2^9\cdot3^9\cdot2\cdot5+2^5\cdot2^3\cdot3^5\cdot5^3\cdot3^3}{5^2\cdot2^8\cdot3^8\cdot2\cdot5-2\cdot2^8\cdot3^8\cdot2^3\cdot5^3}\)

\(=\dfrac{5^3\cdot2^{10}\cdot3^9+5^3\cdot2^8\cdot3^8}{5^3\cdot2^9\cdot3^8-5^3\cdot2^{12}\cdot3^8}\)

\(=\dfrac{5^3\cdot2^8\cdot3^8\left(2^2\cdot3+1\right)}{5^3\cdot2^9\cdot3^8\left(1-2^3\cdot1\right)}=\dfrac{1}{2}\cdot\dfrac{13}{1-9}=-\dfrac{13}{16}\)