(5 nhân 5 mũ 3/125 mũ 2 nhân 49): (5 mũ 6 /434) mũ 7

$\frac{5.5^3}{125^2.49} : (\frac{5^6}{434})^{7}$

= $\frac{5^4}{(5^2)^2.7^2}$x $\frac{(5^6)^7}{(2.7.31)^7}$ 

= $\frac{5^4}{5^4.7^2}$ x $\frac{2^7.7^7.31^7}{5^{42}}$

= $\frac{2^7.7^5.31^7}{5^{42}}$