1.
a) \(3^4\times3^5\times3^6=3^{4+5+6}=3^{15}\)

b) \(5^2\times5^4\times5^5\times25=5^2\times5^4\times5^5\times5^2=5^{2+4+5+2}=5^{13}\)

c) \(10^8\div10^3=10^{8-3}=10^5\)

d) \(a^7\div a^2=a^{7-2}=a^5\)

2.

\(987=900+80+7\\ =9\times100+8\times10+7\\ =9\times10^2+8\times10^1+7\times10^0\)

\(2021=2000+20+1\\ =2\times1000+2\times10+1\times1\\ =2\times10^3+2\times10^1+1\times10^0\)

\(abcde=a\times10000+b\times1000+c\times100+d\times10+e\times1\\ =a\times10^4+b\times10^3+c\times10^2+d\times10^1+e\times10^0\)

còn bài 2

1³ + 2³ + 3³ + 4³ + 5³

= 1 + 8 + 27 + 64 + 125

= 225

Học tốt!!!

8=2^3    ;      20=20^1    ;    60=60^1    ;    90=90^1

16=2^4  ;      27=3^3      ;    81=3^4      ;    100=10^2

3⁵ . 4⁵  = ( 3.4 )⁵ = 12⁵

8⁵ . 2³ = ( 2⁴ )⁵ . 2³ = 2²⁰ . 2³ = 2^{20 + 3} = 2²³

kb với mk nha các bạn

3⁵.4⁵.8⁵.2³= (3 . 4 . 8)³ . 8

3⁵ ; 4⁵ ; 8⁵ ; 2³

a) 3³ . 3⁴ = 3⁷

b) 5² . 5⁷ = 5⁹

c) 7⁵ . 7 = 7⁶

a) \(3^3.3^4=3^{3+4}=3^7\)

b) \(5^2.5^7=5^{2+7}=5^9\)

c) \(7^5.7=7^{5+1}=7^6\)

\(3^3.3^4=3^{3+4}=3^7\)

\(5^2.5^7=5^{2+7}=5^9\)

\(7^5+7=7^{5+1}=7^6\)

Sao chẳng có ai T mik z bất công quá

=2⁹⁸:2²=2^98-2=2⁹⁶

=3²⁶:3⁸=3^26-8=3¹⁸

Mấy bài khác bn lm tương tự

2⁵ . 4³ = 2⁵ . (2²)³ = 2⁵ . 2⁶ = 2^{5 + 6} = 2¹¹

\(2^{11}\)

\(2^5\cdot4^3=2^5\cdot2^6=2^{11}\)

\(\begin{array}{l}{3^3}{.3^4} = {3^{3 + 4}} = {3^7};\\{10^4}{.10^3}  = 10^{4+3}= {10^7};\\{x^2}.{x^5} = x^{2+5} = {x^7}.\end{array}\