đề ko rõ bn nha

bn ko biet doc mai cai chu o duoi a

(169 - 4 mũ 2) (169 -5 mũ 2) ...( 169 - 13 mũ 2)

= (169-4²)(169-5²)...(169-13²)

=(199-4²)(169-5²)...(169-169)

=_____________...0

=       0

a) \(27^7\div9^{10}\)

\(=\left(3^3\right)^7\div\left(3^2\right)^{10}\)

\(=3^{3\times7}\div3^{2\times10}\)

\(=3^{21}\div3^{20}\)

\(=3^1\)

\(=3\)

b) \(125^6\div25^7\)

\(=\left(5^3\right)^6\div\left(5^2\right)^7\)

\(=5^{3\times6}\div5^{2\times7}\)

\(=5^{18}\div5^{14}\)

\(=5^4\)

\(=625\)

c) \(5^{15}\div5^3\)

\(=5^{12}\)

\(=244140625\)

d) \(11^7\div11^3\)

\(=11^4\)

\(=14641\)

e) \(125\div5^2\)

\(=5^2\div5^2\)

\(=5^1\)

\(=5\)

g) \(169\div13^2\)

\(=13^2\div13^2\)

\(=13^1\)

\(=13\)

13.(7x—49)—169=13⁵:13⁴

13.(7x—49)—169=13

13.(7x—49)=13+169

13.(7x—49)=182

7x—49=182:13

7x—49=14

7x=14+49

7x=63

x=63:7

x=9

13 . (7x - 49) - 169 = 13⁵  : 13⁴

13 . (7x - 49) - 169 = 13

       (7x - 49) - 169 = 13:13

       (7x - 49) - 169 = 1  

        7x - 49           = 1 + 169

        7x - 49           = 170

        7x                  = 170 - 49

        7x                  = 121

          x                  = 121 : 7     

          x                  = ?

Bài 3 :

a) 4.(x-5) - 2 ³=2⁴.3

4x-20-8=48

4x=76

x=19

b) 4.x³+15=271

4.x³=256

x³=64

=> x=4

c) ( 2x-3)²= 169

=> 2x-3= 13

2x=16

x=8

 Chúc bạn học tốt !

4*(x-5) - 2^3 = 2^4*3 

4*(x-5) - 8 = 16*3 

4*(x-5) - 8 = 48 

4*(x-5) = 48 + 8 

4*(x-5) = 56 

x- 5 = 56 : 4 

x - 5 = 14 

x = 14 + 5 

x = 19 

Sửa đề : 
( 169-4²).(169-5²) ....(169-13²) 
= (169-4²).(169-5²) ....(169-13²) 
= (169-4²).(169-5²) ...(169-169)
= __________________0
= 0
Học tốt !