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

a)  ( 3 - 4 i ) 2  = 3 2  − 2.3.4i + ( 4 i ) 2  = −7 − 24i

b)  ( 2 + 3 i ) 3  = 2 3  + 3. 2 2 .3i + 3.2. ( 3 i ) 2  + ( 3 i ) 3  = −46 + 9i

c)  [ ( 4   +   5 i )   –   ( 4   + 3 i ) ] 5  = ( 2 i ) 5  = 32i

d)  ( 2 - i 3 ) 2  = −1 − 2i 6

a: \(3\cdot3\cdot3\cdot3\cdot3=3^5\)

b: \(y\cdot y\cdot y\cdot y=y^4\)

c: \(5\cdot p\cdot5\cdot p\cdot2\cdot q\cdot4\cdot q=25\cdot2\cdot4\cdot p^2q^2=2\cdot\left(10qp\right)^2\)

d: \(a\cdot a+b\cdot b+c\cdot c+d\cdot d\cdot d\cdot d=a^2+b^2+c^2+d^4\)

a) 3.3.3.3.3 = 3\(^5\)

b) y.y.y.y = y\(^4\)

c) 5.p.5.p.2.q.4.q = 5\(^2\).p\(^2\).q\(^2\).2\(^3\) 

(2\(^3\) ở đây là vì 2.4 = 2.2.2 = 2\(^3\))

d) a.a + b.b + c.c.c + d.d.d.d = a\(^2\)+b\(^2\)+c\(^3\)+d\(^4\)

1³ + 2³ + 3³ + 4³ + 5³

= 1 + 8 + 27 + 64 + 125

= 225

Học tốt!!!

ta có :

\(3^3.7^3=\left(3.7\right)^3=21^3\)

3³7³=(3.7)³

dung roi

Bài 6: 

a: \(2^{27}=8^9\)

\(3^{18}=9^9\)

b: Vì \(8^9< 9^9\)

nên \(2^{27}< 3^{18}\)

1. a) 7⁴       b) 3.5.15.15 = 3.5.3.5.3.5 = 3³.5³            c) 2³.5²             d) 1000.10.10 = 10.10.10.10.10 = 10⁵

2. 2⁵ = 32                  b) 2⁴ = 81             c) 4³ = 64             d) 5⁴ = 625

3. => 8; 16; 125

đúng 1 k nhé !

thanks bạn nhìu nhìu 

a/ (2⁶.16) :4²

=(2⁶.2²) :(2²)²

=2⁸ : 2⁴=2⁴=16

b/ (5¹⁰:625) : 25

= (5¹⁰:5⁴) :5²

=5⁶ : 5²=5³=625

c/ (81.243):3

= (3⁴.3⁵) :3

= 3⁹ :3=3⁸ =6561

\(\begin{array}{l}a){( - 2)^3}.{( - 2)^4} = {( - 2)^{3 + 4}} = {( - 2)^7}\\b){(0,25)^7}:{(0,25)^3} = {(0,25)^{7 - 3}} = {(0,25)^4}\end{array}\)