5 + 5 x 3 + 5 x 6

= 5 x 1 + 5 x 3 + 5 x 6

=5 x ( 1 + 3 + 6 )

=5 x 10

=50

\(5+5\times3+5\times6\)

\(=5\times(1+3+6)\)

\(=5\times10\)

\(=50\)

a, 48/64 + 7/4 

 = 3/4 + 7/4

 = 10/4

b, 3/8 + 119/56

= 3/8 + 17/8

= 20/8

a)48/64=3/4

3/4+7/4=10/4=5/2

b) 119/56=119:7/56:7=17/8

3/8+17/8=20/8=5/2

k mk nghen ^.-

\(\frac{1}{10}+\frac{1}{30}+\frac{1}{60}+\frac{1}{100}+\frac{1}{150}\)

= \(\frac{1}{10}.\left(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right)\)

= \(\frac{1}{10}.2.\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\right)\)

= \(\frac{1}{5}.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}\right)\)

= \(\frac{1}{5}.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\right)\)

= \(\frac{1}{5}.\left(1-\frac{1}{6}\right)\)

= \(\frac{1}{5}.\frac{5}{6}\)

= \(\frac{1}{6}\)

\(\frac{1}{10}+\frac{1}{30}+\frac{1}{60}+\frac{1}{100}+\frac{1}{150}\)

\(=\frac{1}{10}.\left(1+\frac{1}{3}+\frac{1}{6}+\frac{1}{10}+\frac{1}{15}\right)\)

\(=\frac{1}{10}.2.\left(\frac{1}{2}+\frac{1}{6}+\frac{1}{12}+\frac{1}{20}+\frac{1}{30}\right)\)

\(=\frac{1}{10}.2.\left(\frac{1}{1.2}+\frac{1}{2.3}+\frac{1}{3.4}+\frac{1}{4.5}+\frac{1}{5.6}\right)\)

\(=\frac{1}{10}.2.\left(1-\frac{1}{2}+\frac{1}{2}-\frac{1}{3}+\frac{1}{3}-\frac{1}{4}+\frac{1}{4}-\frac{1}{5}+\frac{1}{5}-\frac{1}{6}\right)\)

\(=\frac{1}{5}.\left(1-\frac{1}{6}\right)\)

\(=\frac{1}{5}.\frac{5}{6}\)

\(=\frac{1}{6}\)

Rất vui vì giúp đc bạn <3

\(\frac{14}{70}\) = \(\frac{2}{10}\) 

\(\frac{75}{300}\) = \(\frac{25}{100}\)

\(\frac{14}{70}=0,2\)

\(\frac{75}{300}=0,25\)

< Chúc bn hok tốt >

BÀI 1 là 16 x 17 x 18 x 19

BÀI 2 KHÔNG BIẾT

BÀI 2 : Rơi vào thứ tư

Số bị chia là: 24 x 8 + 7 = 199.

Đáp số:.....................................

Số bị chia của phép chia đó là:

24 x 8 + 7 = 199

Đáp số: 199

Rất vui vì giúp đc bạn <3

a) (5⁴ + 5⁷) . (8⁹ - 2⁷) . (2⁴ - 4²) 

= (5⁴ + 5⁷) . (8⁹ - 2⁷) . (16 - 16)  

= (5⁴ + 5⁷) . (8⁹ - 2⁷) . 0

= 0

b) (7²⁰⁰³ + 7²⁰⁰²) : 7²⁰⁰¹

= 7²⁰⁰³ : 7²⁰⁰¹ + 7²⁰⁰² : 7²⁰⁰¹

= 7² + 7

= 49 + 7

= 53

c) (169 - 4² ) × ( 169 - 5² ) ×......× ( 169 - 13²)

= (169 - 4² ) × ( 169 - 5² ) ×......× ( 169 - 169)

= (169 - 4² ) × ( 169 - 5² ) ×......× 0

= 0

Tìm x biết

 7 × ( x - 14 ) + 39 = 25 + 279 ÷ 9

=> 7 × ( x - 14 ) + 39 = 25 + 31

=> 7 × ( x - 14 ) + 39 = 56

=> 7 × (x - 14)            = 56 - 39

=> 7 × (x - 14)            = 17

=>         x - 14            = 17 : 7

=>         x - 14            = 17/7

=>         x                   = 17/7 + 14

=>         x                   = 115/7 

\((5^4+4^7)\times(8^9-2^7)\times(2^4-4^2)\)

\(=(5^4+4^7)\times(8^9-2^7)\times0\)

\(=0\)