Question

Tính :

a) \(25^3:5^2\)

b) \(\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{9}{49}\right)^6\)

c) \(3-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2\)

Answer 1

Đây nhé

Answer 2

a) \(25^3:5^2=\left(5^2\right)^3:5^2=5^6:5^2=5^{6-2}=5^4\)

Answer 3

a, 25³:5²=(5²)³:5²=5⁶:5²=5⁴=625

b,\(\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{9}{49}\right)^6=\left(\dfrac{3}{7}\right)^{21}:\left[\left(\dfrac{3}{7}\right)^2\right]^6=\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{3}{7}\right)^{12}=\left(\dfrac{3}{7}\right)^9\)

c,\(3-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2=3-1+\left(\dfrac{1}{2}\right)^2:2=2+\dfrac{1}{8}=\dfrac{17}{8}\)