1,Tính
$100-[75-$ $(7-2)^{2}]$
$=100-[75-$ $5^{2}]$
$=100-(75-25)=100-50=50$
2.Chứng tỏ rằng
$(2^{2})$ $^{3}$ =$2^{2.3}$
= $2^{2}$ .$2^{2}$ .$2^{2}$
= $2^{6}$ =$2^{2.3}$
$(3^{3})$ $^{2}$ =$3^{3.}$ $3^{3}$ =$3^{3+3}$ =$3^{6}$ =$3^{3.2}$
3.So sánh:
$(3^{3})$ $^{2}$ =$3^{3.}$ $3^{3}$ =$3^{3+3}$ =$3^{6}$ =$^{3.2}$
$2^{3}$ .$5^{3}$ $và$ $(2.5)^{3}$
$2^{3}$ .$5^{3}$ =$8.125$ =$1000$ .
$5^{3}$ $=$ ($2.5)^{3}$
$Vậy$ $2^{3}$.$5^{3}$= $(2.5)^{3}$
$3^{2}$ .$5^{2}$= $9.25$=225
( $3.5)^{2}$ =$15^{2}$ =225
$Vậy$ $3^{2}$ .$5^{2}$ =$(3.5)^{2}$