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

a, 25³ : 5²

= ( 5² ) ³ : 5²

= 5⁶ : 5²

= 5 ^6-2 = 5 ⁴

Answer 2

\(a,25^3:5^2=\left(5^2\right)^3:5^2=5^6:5^2=5^4\)

\(b,\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{9}{49}\right)^6=\left(\dfrac{3}{7}\right)^{21}:\left[\left(\dfrac{3}{7}\right)^2\right]^6=\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{3}{7}\right)^{12}=\left(\dfrac{3}{7}\right)^9\)\(c,3-\left(-\dfrac{6}{7}\right)^0+\left(\dfrac{1}{2}\right)^2:2=3+1+0,25:2\)

\(=3+1+0,125=4,125\)

Chúc bn học tốt!

Answer 3

b, ( 3/7 )²¹ : [(3/7)² ]⁶

= ( 3/7 )²¹ : (3/7)¹²

= ( 3/7 )⁹

Answer 4

c, = 3 - 1 + 1/4 : 2

= 3 - 1 + 1/8 = 2 +1/8 = 17/ 8

So easy...