Question

Thực hiện phép tính:

a) \(\dfrac{25^7.125^5}{5^{28}}\)

b) (2\(\dfrac{1}{4}\)+2,5):(-3\(\dfrac{1}{6}\)+2\(\dfrac{1}{7}\))

Answer 1

a) \(\frac{25^{7} . 125^{5}}{5^{28}}= \frac{5^{14}. 5^{15}}{5^{28}}= \frac{5^{29}}{5^{28}} = 5\)

b) \((2\tfrac{1}{4} + 2,5): (-3 \tfrac{1}{6} + 2\tfrac{1}{7})\)

= \(\left ( \frac{9}{4} + 2,5 \right )\) : \(\left (- \frac{19}{6} + \frac{15}{7} \right )\)

= \(\frac{-399}{86}\)

Answer 2

a) \(\dfrac{25^7.125^5}{5^{28}}=\dfrac{5^{14}.5^{15}}{5^{28}}=\dfrac{5^{29}}{5^{28}}=5\)

b) \((2\dfrac{1}{4}2,5):\left(-3\dfrac{1}{6}+2\dfrac{1}{7}\right)\)

\(=\left(\dfrac{9}{4}+\dfrac{5}{2}\right):\left(\dfrac{-19}{6}+\dfrac{15}{7}\right)\)

\(=\dfrac{19}{4}:\dfrac{-43}{42}=\dfrac{-399}{86}\)