1, Rút gọn rồi tính 

a) \(\frac{4}{5}+\frac{3}{15}\)

= \(\frac{4}{5}+\frac{1}{5}\)

= \(\frac{5}{5}\)

= \(1\)

b) \(\frac{2}{3}+\frac{32}{24}\)

= \(\frac{2}{3}+\frac{4}{3}\)

= \(\frac{6}{3}\)

= \(2\)

c) \(\frac{5}{6}+\frac{15}{18}\)

= \(\frac{5}{6}+\frac{5}{6}\)

= \(\frac{10}{6}\)

= \(\frac{5}{3}\)

2, Tính rồi rút gọn 

a) \(\frac{8}{15}+\frac{2}{3}\)

= \(\frac{8}{15}+\frac{10}{15}\)

= \(\frac{18}{15}\)

= \(\frac{6}{5}\)

b) \(\frac{3}{7}+\frac{4}{8}\)

= \(\frac{24}{56}+\frac{28}{56}\)

= \(\frac{52}{56}\)

= \(\frac{13}{14}\)

Đáp án:

a) 1

b) 2

c) 5/3

Bài 3.Tính rồi rút gọn

a)6/5

b) 13/14

a) 4/5+3/15=4/5+1/5=1

b) 2/3+32/24=2/3+4/3=2

c)5/6+15/18=5/6+5/6=5/3

3.

a)8/15+2/3=18/15=6/5

b)3/7+4/8=52/56=13/14

Nhớ k cho mình đó !

Đã hứa thì phải làm

bài 5

a) 

`7/5xx15/14`

`=105/70=3/2`

b)

`8/15xx25/8`

`=200/120=5/3`

c)

`2/15xx5/22`

`=10/330`

`=1/33`

bài 6

chiều rộng cx là đơn vị m phải ko ạ?

diện tích căn phòng là

`11/2xx7/2=77/4(m^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

\(A=\frac{3}{4}.\frac{8}{9}.\frac{15}{16}.....\frac{9999}{10000}\)

\(=\frac{1.3}{2.2}.\frac{2.4}{3.3}.\frac{3.5}{4.4}......\frac{99.101}{100.100}\)

\(=\frac{1.2.3...99}{2.3.4....100}.\frac{3.4.5....101}{2.3.4....100}\)

\(=\frac{1}{100}.\frac{101}{2}\)

\(=\frac{101}{200}\)

a: \(\dfrac{15}{8}-\dfrac{13}{8}=\dfrac{15-13}{8}=\dfrac{2}{8}=\dfrac{1}{4}\)

b: \(\dfrac{7}{15}-\dfrac{2}{15}=\dfrac{7-2}{15}=\dfrac{5}{15}=\dfrac{1}{3}\)

c: \(\dfrac{11}{12}-\dfrac{2}{12}=\dfrac{11-2}{12}=\dfrac{9}{12}=\dfrac{3}{4}\)

d: \(\dfrac{19}{7}-\dfrac{5}{7}=\dfrac{19-5}{7}=\dfrac{14}{7}=2\)

Rút gọn rồi tính:                                                                                                                                               \(a.\frac{16}{24}-\frac{1}{3}=\frac{2}{3}-\frac{1}{3}=\frac{1}{3}\)

\(b.\frac{4}{5}-\frac{12}{60}=\frac{4}{5}-\frac{1}{5}=\frac{3}{5}\)

Tính rồi rút gọn:

\(a.\frac{17}{6}-\frac{2}{6}=\frac{15}{6}\)

\(b.\frac{16}{15}-\frac{11}{15}=\frac{5}{15}=\frac{1}{3}\)

\(c.\frac{19}{12}-\frac{13}{12}=\frac{6}{12}=\frac{1}{2}\)

1a2/3-1/3=1/3            c4/5-1/5=3/5             tinh roi rut gon 17/6-2/6=15/6=5/2             16/15-11/15=5/15=1/3           19/12-13/12=6/12=1/2

chuc bn hoc tot

lớp 1 à cu

a) \(\dfrac{21}{15}\) + \(\dfrac{2}{5}\) = \(\dfrac{9}{5}\)
b)  \(\dfrac{6}{16}\) + \(\dfrac{1}{8}\) = \(\dfrac{1}{2}\)

c)  \(\dfrac{3}{12}\) + \(\dfrac{3}{4}\) = 1

( 2/5 +3/4 ) * 2/3 - 8/15 = 23/20 * 2/3 -8/15

= 23/30 - 8/15 = 7/30

là 7/30

12/18 + 12/42 = 2/3 + 2/7 = 14/21 + 6/21 = 20/21

1/2 + 2/4 + 3/6 + 4/8 + 5/10 + 6/12

= 1/2 + 1/2 + 1/2 + 1/2 + 1/2 + 1/2

= 1/2 x 6

=6/2

=3

Còn phần D thì sao😶

tra hieu gi ca

\(\frac{1}{4}+\frac{3}{5}=\frac{17}{20}\)

\(\frac{5}{2}+\frac{7}{9}=\frac{59}{18}\)

\(\frac{3}{2}+\frac{2}{3}=\frac{13}{6}\)

\(\frac{4}{5}+\frac{3}{2}=\frac{23}{10}\)

\(\frac{4}{5}+\frac{3}{15}=\frac{4}{5}+\frac{1}{5}=1\)

\(\frac{2}{3}+\frac{32}{24}=\frac{2}{3}+\frac{4}{3}=2\)

\(\frac{5}{6}+\frac{15}{18}=\frac{5}{6}+\frac{5}{6}=\frac{10}{6}=\frac{5}{3}\)

\(\frac{8}{15}+\frac{2}{3}=\frac{8}{15}+\frac{10}{15}=\frac{18}{15}=\frac{6}{5}\)

\(\frac{3}{7}+\frac{4}{8}=\frac{24}{56}+\frac{28}{56}=\frac{52}{56}=\frac{13}{14}\)

_HT_

Murad trả lời đúng rồi đó!