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\(a,\frac{2}{7}:\frac{4}{5}=\frac{2}{7}\times\frac{5}{4}=\frac{10}{28}=\frac{5}{14}\)
\(b,\frac{3}{8}:\frac{9}{4}=\frac{3}{8}\times\frac{4}{9}=\frac{12}{72}=\frac{1}{6}\)
\(c,\frac{8}{21}:\frac{4}{7}=\frac{8}{21}\times\frac{7}{4}=\frac{56}{84}=\frac{2}{3}\)
\(d,\frac{5}{8}:\frac{15}{8}=\frac{5}{8}\times\frac{8}{15}=\frac{40}{120}=\frac{1}{3}\)
A,\(\frac{2}{7}:\frac{4}{5}=\frac{2}{7}\times\frac{5}{4}=\frac{10}{28}=\frac{5}{14}\)
B,\(\frac{3}{8}:\frac{9}{4}=\frac{3}{8}\times\frac{4}{9}=\frac{12}{72}=\frac{1}{6}\)
C.\(\frac{8}{21}:\frac{4}{7}=\frac{8}{21}\times\frac{7}{4}=\frac{56}{84}=\frac{2}{3}\)
D.\(\frac{5}{8}:\frac{15}{8}=\frac{5}{8}\times\frac{8}{15}=\frac{40}{120}=\frac{1}{3}\)
Đúng 100%
2/7 / 1/7 = 10/28 = 5/14
3/8 / 9/4 = 12/72 = 2/12
8/21 / 4/7 = 56/84 = 14/21
5/8 / 15 / 8 = 1/24 / 8 = 1/192
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
\(\frac{9}{12}+\frac{4}{7}\)
\(=\frac{3}{4}+\frac{4}{7}\)
\(=\frac{37}{28}\)
\(\frac{5}{10}+\frac{21}{28}\)
\(=\frac{1}{2}+\frac{3}{4}\)
\(=\frac{5}{4}\)
\(\frac{7}{9}+\frac{15}{27}\)
\(=\frac{7}{9}+\frac{5}{9}\)
\(=\frac{12}{9}\)
rút gọn phân số :
4/5+21/15=4/5+7/5=11/5
8/9-25/45=8/9-5/9=3/9
tính :
5/6+2/7+15/6=5/6+15/6+2/7
=10/3+2/7=76/21
7/8-9/6.7/8=7/8-21/16=-7/16
chúc bạn học tốt !!!
BÀI 1
A) \(\frac{9}{12}+\frac{4}{7}=\frac{3}{4}+\frac{4}{7}=\frac{37}{28}\)
B)\(\frac{5}{10}+\frac{21}{28}=\frac{1}{2}+\frac{3}{4}=\frac{5}{4}\)
C)\(\frac{7}{9}+\frac{15}{27}=\frac{7}{9}+\frac{5}{9}=\frac{12}{9}=\frac{4}{3}\)
BÀI 2:
SỐ PHẦN BỂ ĐÃ CHỨA XĂNG SAU 2 LẦN ĐƯỢC BƠM LÀ:
\(\frac{3}{8}+\frac{1}{4}=\frac{5}{8}\)(BỂ CHỨA XĂNG)
Đ/S: 5/8 BỂ CHỨA XĂNG
CHÚC BN HỌC TỐT!!!
a) \(\frac{1}{5}:\frac{2}{15}=\frac{1}{5}\times\frac{15}{2}\)
\(=\frac{15}{10}=\frac{3}{2}\)
b)\(\frac{3}{7}:\frac{9}{14}=\frac{3}{7}\times\frac{14}{9}\)
\(=\frac{42}{63}=\frac{2}{3}\)
c) \(\frac{7}{12}:\frac{21}{24}=\frac{7}{12}\times\frac{24}{21}\)
\(=\frac{168}{252}=\frac{2}{3}\)
d) \(\frac{9}{13}:\frac{27}{26}=\frac{9}{13}\times\frac{26}{27}\)
\(=\frac{234}{351}=\frac{2}{3}\)
k nha
A/ 15/10 = 3/2
B/ 42/63 = 2/3
C/ 168/252 = 2/3
D/ 234/351 = 2/3
a)=2/3-1/3= 1/3
b)=7/5-3/5= 4/5
c)=3/2-1/2= 2/2=1
d)=11/4-3/4= 8/4= 2
a: \(\dfrac{1}{8}+\dfrac{5}{8}=\dfrac{1+5}{8}=\dfrac{6}{8}=\dfrac{3}{4}\)
b: \(\dfrac{1}{15}+\dfrac{4}{15}=\dfrac{1+4}{15}=\dfrac{5}{15}=\dfrac{1}{3}\)
c: \(\dfrac{5}{9}+\dfrac{7}{9}=\dfrac{5+7}{9}=\dfrac{12}{9}=\dfrac{4}{3}\)
d: \(\dfrac{23}{100}+\dfrac{27}{100}=\dfrac{23+27}{100}=\dfrac{50}{100}=\dfrac{1}{2}\)
a) 18+58=1+58=68=3418+58=1+58=68=34
b) 115+415=1+415=515=13115+415=1+415=515=13
c) 59+79=5+79=129=4359+79=5+79=129=43
d) 23100+27100=23+27100=50100=12
a: =8/4-1/4=7/4
b: =3/9=1/3
c: =5/7-4/7=1/7
a,\(\dfrac{7}{4}\)
b,\(\dfrac{1}{3}\)
c,\(\dfrac{1}{7}\)