a, \(\frac{-3}{7}\)+ \(\frac{2}{9}\)=  \(\frac{-13}{63}\)

b, \(\frac{-5}{11}\)+ \(\frac{6}{7}\)= \(\frac{31}{77}\)

c, \(\frac{334}{335}\)+ \(\frac{-4}{335}\)= \(\frac{66}{67}\)

\(a)\frac{36}{-84}+\frac{100}{450}=\frac{-36}{84}+\frac{100}{450}\)

Rút gọn : \(\frac{-36}{84}=\frac{-36:12}{84:12}=\frac{-3}{7}\)

\(\frac{100}{450}=\frac{100:50}{450:50}=\frac{2}{9}\)

B₁ : 7 = 7

 9 = 3²

^{\(\Rightarrow MSC=BCNN(7,9)=7\cdot3^2=63\)}

B2 : Thừa số phụ : 

      63 : 7 = 9

     63 : 9 = 7

B3 : Quy đồng :

\(\frac{36}{-84}=\frac{-36}{84}=\frac{-3}{7}=\frac{-3\cdot9}{7\cdot9}=\frac{-27}{63}\)

\(\frac{100}{450}=\frac{2}{9}=\frac{2\cdot7}{9\cdot7}=\frac{14}{63}\)

\(\Rightarrow\frac{-3}{7}+\frac{2}{9}=\frac{-27}{63}+\frac{14}{63}=\frac{-27+14}{63}=\frac{-13}{63}\)

b,c, Tự làm

Ok cảm ơn 2 bạn

65/91 + -33/55=4/35

36/-84 + 100/450=-13/63

-650/1430 + 588/686=31/77

20004/2010 + 8/-670=666/67

\(-\frac{650}{1430}+\frac{588}{686}=\frac{31}{77}\)

\(\frac{2004}{2010}+\frac{8}{-670}=\frac{66}{67}\)

-650/1430+588/686=31/77

2004/2010+8/-670=66/67

-650/1430+588/686

=> -650/1430+588/686=31/77

2004/2010+8/-670

=> 2004/2010+8/-670=66/67

Tính :

a) 65 / 91  +  -33 / 55

\(=\frac{5}{7}-\frac{3}{5}=\frac{4}{35}\)

b) 36 / -84  +  100 // 450

\(=\frac{-3}{7}+\frac{2}{9}=-\frac{13}{63}\)

c) -650 / 1430  +  588 / 686

\(=\frac{5}{11}+\frac{6}{7}=\frac{101}{77}\)

d) 2004 / 2010 + 8 / -670

=\(=\frac{334}{335}-\frac{4}{335}=\frac{66}{67}\)

ths ban nha

31/77

-650/1430+588/686 = -5/11+49/53 = 31/77

a, \(\frac{65}{91}+\frac{-33}{55}=\frac{5}{7}+\frac{-3}{5}=\frac{4}{35}\)

b, \(\frac{36}{-84}+\frac{100}{450}=\frac{-3}{7}+\frac{2}{9}=-\frac{13}{63}\)

c, \(\frac{-650}{1430}+\frac{588}{686}=\frac{-5}{11}+\frac{6}{7}=\frac{31}{77}\)

d, \(\frac{2004}{2010}+\frac{8}{-670}=\frac{334}{335}+\frac{-4}{335}=\frac{66}{67}\)

thank you

\(\frac{-650}{1430}+\frac{588}{686}=\frac{31}{77}\)

\(\frac{2004}{2010}+\frac{8}{-670}=\frac{66}{67}\)

bạn vô kham khỏa nha

87013248405.html

kham khỏa nha

87013248405.html