a.\(\frac{17.5-17}{-17}=\frac{17.4}{-17}=-4\)

b.\(\frac{49.8}{49}=8\)

a) \(\frac{17.5-17}{3-20}\)= \(\frac{85-17}{3-20}\)= \(\frac{68}{-17}\)=-4

b) \(\frac{49+7.49}{49}\)= \(\frac{49+343}{49}\)= \(\frac{392}{49}\)= 8

CHÚC BẠN HỌC TỐT

Bài 1: Tính

\(a.\frac{15}{16}-\frac{7}{16}=\frac{15-7}{16}=\frac{8}{16}=\frac{1}{2}\)

\(b.\frac{7}{4}-\frac{3}{4}=\frac{7-3}{4}=\frac{4}{4}=1\)

\(c.\frac{9}{5}-\frac{3}{5}=\frac{9-3}{5}=\frac{6}{5}\)

\(d.\frac{17}{49}-\frac{12}{49}=\frac{17-12}{49}=\frac{5}{49}\)

Bài 2:Rút gọn rồi tính

\(a.\frac{2}{3}-\frac{3}{9}=\frac{2}{3}-\frac{1}{3}=\frac{2-1}{3}=\frac{1}{3}\)

\(b.\frac{7}{5}-\frac{15}{25}=\frac{7}{5}-\frac{3}{5}=\frac{7-3}{5}=\frac{4}{5}\)

Học tốt. K cho mik nha

Trl :

Bạn kia làm đúng rồi nhé !

Học tốt nhé bạn @

40000000000000+09999999999999999999999=.....,..............,.......,........

1.  

19/36

2

x=8,y=5;x=4,y=0

3

7/11

4

*ko hiểu *

4.

49 : \(\frac{5}{7}\)= 49 x \(\frac{7}{5}\)=  \(\frac{49}{1}\)x \(\frac{7}{5}\)= \(\frac{343}{5}\) 

\(\frac{343}{5}\)x  \(49\)= \(\frac{343}{5}\)x \(\frac{49}{1}\)= \(\frac{16807}{5}\)

còn các bài trên y hệt của bạn Bùi bạch dương

Bài 1: Rút gọn

\(A=\dfrac{-56\cdot49+\left(-49\right)\cdot44}{73\cdot14+\left(-14\right)\cdot\left(-27\right)}\)

\(=\dfrac{49\cdot\left(-56-44\right)}{14\cdot\left(73+27\right)}\)

\(=\dfrac{-49\cdot100}{14\cdot100}=\dfrac{-7}{2}\)

4A=4+4²+4³+4⁴+...+4⁵⁰

4A-A=3A=4⁵⁰-1

A=\(\frac{4^{50}-1}{3}\)

\(A=\dfrac{17^{100}+17^{96}+17^{92}+....+17^4+1}{17^{102}+17^{100}+17^{98}+....+17^2+1}\)

Gọi \(17^{100}+17^{96}+17^{92}+....+17^4+1\) là B

\(B=17^{100}+17^{96}+17^{92}+....+17^4+1\\ 17^4\cdot B=17^{104}+17^{100}+17^{96}+......+17^8+17^4\\ 17^4\cdot B-B=\left(17^{104}+17^{100}+17^{96}+......+17^8+17^4\right)-\left(17^{100}+17^{96}+17^{92}+....+17^4+1\right)\\ B\cdot\left(17^4-1\right)=17^{104}-1\\ B=\dfrac{17^{104}-1}{17^4-1}\)

Gọi \(17^{102}+17^{100}+17^{98}+....+17^2+1\) là C

\(C=17^{102}+17^{100}+17^{98}+....+17^2+1\\ C\cdot17^2=17^{104}+17^{102}+17^{100}+17^{98}+....+17^2\\ C\cdot17^2-C=\left(17^{104}+17^{102}+17^{100}+17^{98}+....+17^2\right)-\left(17^{102}+17^{100}+17^{98}+....+17^2+1\right)\\ C\cdot\left(17^2-1\right)=17^{104}-1\\ C=\dfrac{17^{104}-1}{17^2-1}\)

=>

 \(A=B:C\\ A=\dfrac{17^{104}-1}{17^4-1}:\dfrac{17^{104}-1}{17^2-1}\\ A=\dfrac{17^2-1}{17^4-1}\)

cảm ơn bạn

A = \(\dfrac{T}{M}\)

M = T + (\(17^{102}+17^{98}+17^{94}+...+17^2\))

M = T + \(17^2\left(17^{100}+17^{96}+17^{92}+...+17^0\right)\)

M = T + \(17^2\cdot\) T = T(\(1+17^2\))

=> A = \(\dfrac{T}{T\left(1+17^2\right)}=\dfrac{1}{1+17^2}\)

a. \(\dfrac{8,5-8,2}{16}=\dfrac{0,3}{16}=\dfrac{3}{160}\)

b. \(\dfrac{2\cdot14}{7\cdot8}=\dfrac{1\cdot2}{1\cdot4}=\dfrac{2}{4}=\dfrac{1}{2}\)

c. \(\dfrac{11\cdot4-11}{2-13}=\dfrac{11\left(4-1\right)}{-11}=\dfrac{1\cdot3}{-1}=-3\)

d. \(\dfrac{49+7\cdot49}{49}=\dfrac{49\cdot\left(1+7\right)}{49}=\dfrac{8}{1}=8\)

\(=\dfrac{7^{48}\cdot5^{30}\cdot2^8-5^{30}\cdot7^{49}\cdot2^{10}}{3^2\cdot2^2\cdot5^2\cdot7^{48}}\)

\(=\dfrac{7^{48}\cdot5^{30}\cdot2^8\left(1+7\cdot4\right)}{3^2\cdot2^2\cdot5^2\cdot7^{48}}=\dfrac{5^{28}\cdot2^6\cdot12}{3^2}=\dfrac{5^{28}\cdot2^8}{3}\)

\(A=\frac{49^{24}.125^{10}.2^8-5^{30}.7^{49}.4^5}{5^{29}.16^2.7^{43}}\)

\(A=\frac{7^{48}.5^{30}.2^8-5^{30}.7^{49}.2^{10}}{5^{29}.2^8.7^{43}}\)

\(A=\frac{5^{30}.7^{48}.2^8.\left(1-7.2^2\right)}{5^{29}.2^8.7^{43}}=5.7^3.\left(1-7.2^2\right)=1715.\left(-27\right)=-46305\)

\(A=\frac{\left(7^2\right)^{24}.\left(5^3\right)^{10}.2^8-5^{30}.7^{49}.\left(2^2\right)^5}{5^{29}\left(2^4\right)^2.7^{43}}=\frac{7^{48}.5^{30}.2^8-5^{30}.7^{49}.2^{10}}{5^{29}.2^8.7^{43}}=\frac{7^{48}.5^{30}.2^8\left(1-7.2^2\right)}{5^{29}.2^8.7^{43}}\)

=\(7^5.5.\left(-27\right)=-2268945\)

A = 7⁵*5*-27