\(\frac{5^{20}}{5^{15.6}+5^{15}.19}\)

mk viết nhầm nha \(\frac{5^{20}}{5^{15.6}+5^{15.19}}=\frac{5^{20}}{5^{90}+5^{285}}\)

đúng ko

5²⁰ : (5¹⁵.6 + 5¹⁵.19)

= 5²⁰ : [5¹⁵(6 + 9)]

= 5²⁰ : (5¹⁵.15)

= \(\frac{625}{3}\)

\(5^{20}:\left(5^{15}.6+5^{15}.19\right)=5^{20}:\left[5^{15}\left(6+19\right)\right]\)

\(=5^{20}:\left(5^{15}.25\right)=5^{20}:\left(5^{15}.5^2\right)=5^{20}:5^{17}\)

\(=5^3=125\)

Bài làm

   5²⁰ : ( 5¹⁵ . 6 + 5¹⁵ . 19 )

= 5²⁰ : [ 5¹⁵ . ( 6 + 19 ) ]

= 5²⁰ : [ 5¹⁵ . 25 ]

= 5²⁰ : [ 5¹⁵ . 5² ]

= 5²⁰ : 5¹⁵ 

= 5⁵ 

= 3125

# Học tốt #

  5²⁰ : (5¹⁵.6+5¹⁵.19)

=5²⁰:[5¹⁵.(6+19)]

=5²⁰:[5¹⁵.25]

=5²⁰:[5¹⁵.5² ]

=5²⁰:[5¹⁵⁺² ]

=5²⁰ : 5¹⁷

=5^20-17

=5³

=125

chúc bạn học tốt 

=5^20:[5^15(6+9)]
=5^20:[5^15.15]
=5^20.[1/5^15.1/15)
=5^20.1/5^15.1/15
=5^20:5^15.1/15
=5^20-15.1/15
=5^5.1/15
=5^5/15
=5.5^4/5.3
=5^4/3
(=625/3)

ở dưới nhầm số 

1166.4106359

\(-\frac{5}{16}\cdot\frac{120}{5}< x< -\frac{7}{15}\cdot\frac{9}{14}\)

\(\Rightarrow-\frac{15}{2}< x< -\frac{3}{10}\)

\(\Rightarrow-\frac{75}{10}< x< -\frac{3}{10}\)

Vậy x \(\in\){ \(-\frac{74}{10};-\frac{73}{10};-\frac{72}{10};...;-\frac{4}{10}\) }

a -3/2

b -1/9