Đáp án:
Giải thích các bước giải:
bài 1:
a,tính
$6^{12}$:$6^{10}$ =$6^{12-10}$ =$6^{2}$
$2^{28}$:$2^{25}$=$2^{28-25}$=$2^{3}$
$8^{9}$:$8^{8}$=$8^{9-8}$=$8^{1}$
b,
1975=1000+900+70+5
=1.1000+9.100+7.10+5
=1.$10^{3}$+9.$10^{2}$+7.$10^{1}$+5.$10^{0}$
tương tự;
2015=2.$10^{3}$+0.$10^{2}$+1.$10^{1}$+5.$10^{0}$
c,
$3^{3}$.18-$3^{3}$ .15 =$3^{3}$.(18-15) =$3^{3}$.3=$3^{4}$
$3^{6}$. $3^{2}$+2. $3^{8}$ =$3^{8}$.(1+2)=$3^{8}$.3=$3^{9}$
196 :$14^{2}$=$14^{2}$:$14^{2}$=$1^{2}$
$5^{3}$.25:$5^{2}$=($5^{3}$:$5^{2}$).25=$5^{1}$.25=$5^{3}$