8^5 x (-5)^8 + (-2)^5 . 10^9 ————————————– 2^16 x 5^7 + 20^8 Đây là phân số, giúp mình tính nhanh nhá

Đáp án:

 $\dfrac{-5}{8}$

Giải thích các bước giải:

 $\dfrac{8^5.(-5)^8+(-2)^5.10^9}{2^{16}.5^7+20^8}\\
=\dfrac{8^5.5^8-2^5.10^9}{2^{16}.5^7+20^8}\\
=\dfrac{(2^3)^5.5^8-2^5.(2.5)^9}{2^{16}.5^7+(2^2.5)^8}\\
=\dfrac{2^{15}.5^8-2^5.2^9.5^9}{2^{16}.5^7+2^{16}.5^8}\\
=\dfrac{2^{15}.5^8-2^{14}.5^9}{2^{16}.5^7+2^{16}.5^8}\\
=\dfrac{2^{14}.5^8(2-5)}{2^{16}.5^7(1+5)}\\
=\dfrac{5.(-3)}{2^2.6}\\
=\dfrac{5.(-1).3}{2^2.6}\\
=\dfrac{-5}{8}$