Bài $5$
$a$) `(3/7 + 1/2)^2 = (13/14)^2 = 169/196`
$b$) `(3/4 - 5/6)^2 = (-1/12)^2=1/{144}`
$c$) $\dfrac{5^4.20^4}{25^5.4^5} = \dfrac{5^4.4^4.5^4}{5^{10} . 4^5} = \dfrac{1}{100}$
Bài $6$.
$a$) `(2/3)^3 = 8/27`
$b$) `(-2/3)^3 = -8/27`
$c$) `(-1 3/4)^2 = (-7/4)^2 = 49/16`
$d$) `(0,1)^4 = (1/10)^4 = 1/10000`