Theo quy ước với mọi phân số lớn hơn 0 thì ta có:
\(\dfrac{a}{b}>0=>\dfrac{a}{b}< \dfrac{a+n}{b+n}\left(n\in N;n\ne0\right)\)
Áp dụng với bài trên ta => ĐPCM
CHÚC BẠN HỌC TỐT.......
tính hợp lí:
a)\(\left(4\dfrac{5}{37}-3\dfrac{4}{5}+8\dfrac{15}{29}\right)-\left(3\dfrac{5}{37}-6\dfrac{14}{29}\right)\)
b) \(60\dfrac{7}{13}+50\dfrac{8}{13}-11\dfrac{2}{13}\)
c) \(\dfrac{\dfrac{2}{3}+\dfrac{2}{7}-\dfrac{1}{14}}{-1-\dfrac{3}{7}+\dfrac{3}{28}}\)
1.So Sánh
a) A=\(\dfrac{11}{2017}+\dfrac{4}{2019}và\) B=\(\dfrac{10}{2017}+\dfrac{10}{2019}\)
b) M=\(\dfrac{1}{5}+\dfrac{1}{12}+\dfrac{1}{13}+\dfrac{1}{14}+\dfrac{1}{30}+\dfrac{1}{61}+\dfrac{1}{62}và\dfrac{1}{2}\)
c) E=\(\dfrac{4116-14}{10290-35}và\) K=\(\dfrac{2929-101}{2.1919+404}\)
bài 1 so sánh
a) \(\dfrac{45}{105}va\dfrac{84}{147}\)
b) \(\dfrac{-12}{19}va\dfrac{-14}{17}\)
c) \(\dfrac{13}{19}va\dfrac{47}{53}\)
d) \(\dfrac{-29}{38}va\dfrac{-13}{22}\)
bài 1 : so sánh :
a) \(\dfrac{23}{21}\)và\(\dfrac{21}{23}\)
b)\(\dfrac{19}{26}\)và \(\dfrac{21}{25}\)
bài 2 : sắp sếp các phân số sau từ bé đến lớn :
a)\(\dfrac{7}{36};\dfrac{24}{36};\dfrac{13}{36};\dfrac{1}{36};\dfrac{43}{36};\dfrac{36}{36}\)
b)\(\dfrac{-3}{10};\dfrac{-31}{100};\dfrac{-297}{1000};\dfrac{10000}{-3056}\)
c)\(\dfrac{13}{20};\dfrac{7}{20};\dfrac{9}{4};\dfrac{2}{5};\dfrac{1}{2}\)
d)\(\dfrac{13}{21};\dfrac{152}{17};\dfrac{13}{17};\dfrac{-5}{21}\)
e)\(\dfrac{-1}{2};\dfrac{3}{-4};\dfrac{-2}{3};\dfrac{4}{-5}\)
BT3: Tìm x, biết
13) \(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=\dfrac{-7}{4}+\dfrac{1}{4}:\dfrac{1}{8}\)
14) \(\dfrac{11}{13}-\left(\dfrac{5}{42}-x\right)=-\left(\dfrac{15}{28}-\dfrac{11}{13}\right)\)
\(A=1\dfrac{13}{15}.25.\dfrac{1}{100}.3+\left(\dfrac{8}{15}-\dfrac{78}{60}\right):1\dfrac{23}{24}\)
Tính giá trị biểu thức :
B = \(1\dfrac{13}{15}\). (0,5)2 . 3+ \(\left(\dfrac{8}{15}-1\dfrac{19}{60}\right):1\dfrac{23}{24}\)
Tính hợp lí giá trị biểu thức :
C = \(49\dfrac{8}{23}-\left(5\dfrac{7}{32}+14\dfrac{8}{23}\right)\)
Giair hộ nhé !!
Tính :
a) \(\dfrac{17}{23}.\dfrac{8}{16}.\dfrac{23}{17}.\left(-80\right).\dfrac{3}{4}\)
b) \(\dfrac{5}{11}.\dfrac{18}{29}-\dfrac{5}{11}.\dfrac{8}{29}+\dfrac{5}{11}.\dfrac{19}{29}\)
c) \(\left(\dfrac{13}{23}+\dfrac{1313}{2323}-\dfrac{131313}{232323}\right).\left(\dfrac{1}{3}+\dfrac{1}{4}-\dfrac{7}{12}\right)\)
d) \(\dfrac{1^2}{1.2}.\dfrac{2^{2^{ }}}{2.3}.\dfrac{3^2}{3.4}.\dfrac{4^2}{4.5}.\dfrac{5^2}{5.6}.\dfrac{6^2}{6.7}.\dfrac{7^2}{7.8}.\dfrac{8^2}{8.9}.\dfrac{9^2}{9.10}\)
e) \(\dfrac{2^2}{3}.\dfrac{3^2}{8}.\dfrac{4^2}{15}.\dfrac{5^2}{24}.\dfrac{6^2}{35}\dfrac{7^2}{48}.\dfrac{8^2}{63}.\dfrac{9^2}{80}\)
\(\dfrac{-5}{9}+1\dfrac{5}{9}\cdot\left(\dfrac{3}{4}-\dfrac{2}{5}\right):7^2\)
\(1\dfrac{13}{15}\cdot0,75-\left(\dfrac{104}{195}+25\%\right)\cdot\dfrac{24}{47}-3\dfrac{12}{13}:3\)
\(1\dfrac{13}{15}\cdot\left(0,5\right)^2\cdot3+\left(\dfrac{8}{15}+1\dfrac{19}{60}\right):1\dfrac{23}{24}\)