\(\frac{5}{6}+6\frac{1}{6}.\left(11\frac{94}{1591}-6\frac{38}{1951}\right):8\frac{11}{43}\)

= \(\frac{5}{6}+\frac{37}{6}.\frac{8011}{1591}:8\frac{11}{43}\)

= \(\frac{5}{6}+\frac{8011}{258}:\frac{355}{43}\)

= \(\frac{5}{6}+\frac{344473}{91590}\)

= \(\frac{1631}{355}\)

-251/418

Bạn xem lại đã đánh đúng đề chưa chứ mình tính k có ra :) 

7/38-9/11+7/38.4/11:7/38.2/11 nha ><

𝑎=−251/418

\(\frac{2^{15}.9^4}{6^7.8^2}\)

\(=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.\left(2^3\right)^2}\)

\(=\frac{2^{15}.3^8}{2^7.3^7.2^6}\)

\(=\frac{2^{15}.3^8}{2^{13}.3^7}\)

\(=2^2.3\)

\(=12\)

_Chúc bạn học tốt_

\(\frac{2^{15}.9^4}{6^7.8^2}=\frac{2^{15}.\left(3^2\right)^4}{\left(2.3\right)^7.\left(2^3\right)^2}=\frac{2^{15}.3^8}{2^7.3^7.2^6}=\frac{2^{15}.3^8}{2^{13}.3^7}=2^2.3=12\)

\(\frac{2^{15}\cdot9^4}{6^7\cdot8^2}\)

\(=\frac{2^{15}\cdot\left(3^2\right)^4}{\left(2\cdot3\right)^7\cdot\left(2^3\right)^2}\)

\(=\frac{2^{15}\cdot3^8}{2^7\cdot3^7\cdot2^6}=\frac{2^{15}\cdot3^8}{2^{13}\cdot3^7}\)

Rút gọn => \(=2^2\cdot3=4\cdot3=12\)

hok tốt ...

7⁶ + 7⁵ - 7⁴

= 7⁴( 7² + 7 - 1 )

= 7⁴ . 55

= 7⁴ . 5 . 11 chia hết cho 11

Ta có :

7 ⁶ + 7 ⁵ - 7 ⁴ 

= 7 ⁴ ( 7 ² + 7 - 1 )

= 7 ⁴ . 55

= 7 ⁴ . 5 . 11 chia hết cho 11

Vậy 7 ⁶ + 7 ⁵ - 7 ⁴ chia hết cho 11

mình còn ko bt cơ mà mai nộp r

mik chỉ lm đc 1 câu thôi mong bn like cho
(13911:3849−5211:3849):(4938.511)={(13+911).4938−(5+211).4938}:(4938.511)=4938.(13−5+911−211):(4938.511)=4938.(8+711):(4938.511)=(8+711):511=19

A=3.(1/1.2+1/2.3+1/3.4+.....+1/399.400)

A=3.(1/1-1/2+1/2-1/3+......+1/399-1/400)

A=3.(1-1/400)

A=3.399/400

A=1197/400

A=3.(1/1.2+1/2.3+1/3.4+.....+1/399.400)

A=3.(1/1-1/2+1/2-1/3+......+1/399-1/400)

A=3.(1-1/400)

A=3.399/400

A=1197/400