a) -15/90= -5/30= -1/6

120/600=1/5

-75/150= -25/50= -1/2

b)3.4+3.7/6.5+9

=3.(4+7)/3.2+3 .3

=11/2+3.3

=11/11=1

6.9-2.17/63.3-11.9

=2.3.3.3-2.17/7.3.3-11.3.3

=2-2.17/7.3-11

= 2-2.17/10

=2-2.17/2.5

=2-17/5

=-15/5=-3

8x1=8 

8x2=16

8x3=24

8x4=32

8x5=40

8x6=48

8x7=56

8x8=64

8x9=72

8x10=80

8x1=8

8x2=16

8x3=24

8x4=32

8x5=40

8x6=48

8x7=56

8x8=64

8x9=72

8x10=80

minh nhanh nhat k nha

=8

=16

=24

=32

=40

=48

=56

=64

=72

=80

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

8x1=8

8x2=16

8x3=24

8x4=32

8x5=40

8x6=48

8x7=56

8x8=64

8x9=72

8x10=80

8 x 1 = 8

8 x 2 = 16

8 x 3 = 24

8 x 4 = 32

8 x 5 = 40 

8 x 6 = 48

8 x 7 = 56

8 x 8 = 64

8 x 9 = 72

8 x 10 = 80

8x1=8

8x2=16

8x3=24

8x4=32

8x5=40

8x6=48

8x7= 56

8x8=64

8x9= 72

8x10=80

\(a,\dfrac{x}{7}=\dfrac{6}{21}\Rightarrow x.21=7.6=42\\ \Rightarrow x=2\\ b,\dfrac{1}{2}=\dfrac{x}{12}\Rightarrow1.12=2.x=12\\ \Rightarrow x=6\\ c,\dfrac{-7}{6}=\dfrac{x}{12}\Rightarrow-7.12=6.x=-84\\ \Rightarrow x=-14\)

mình đang cần gấp, giúp mình với ạ

câu d là 6 phần mấy đấy ạ?

Rút gọn rồi tính:

a) $\frac{16}{24}–\frac{1}{3}=\frac{2}{3}–\frac{1}{3}=\frac{2–1}{3}=\frac{1}{3}$     

b) $\frac{4}{5}–\frac{12}{60}=\frac{4}{5}–\frac{1}{5}=\frac{3}{5}$

Tính rồi rút gọn:

a) $\frac{17}{6}–\frac{2}{6}=\frac{17–2}{6}=\frac{15}{6}=\frac{5}{2}$             

b) $\frac{16}{15}–\frac{11}{15}=\frac{16–11}{15}=\frac{5}{15}=\frac{1}{3}$

c) $\frac{19}{12}–\frac{13}{12}=\frac{19–13}{12}=\frac{6}{12}=\frac{1}{2}$

D

D

D

\(\dfrac{90}{126}=\dfrac{90:18}{126:18}=\dfrac{5}{7}\)

D

D.5 phần 7

Ta có: \(\dfrac{21}{35}\)=\(\dfrac{21:7}{35:7}\)=\(\dfrac{3}{5}\)

Vậy \(\dfrac{3}{5}\)+\(\dfrac{5}{4}\)=\(\dfrac{12}{20}\)+\(\dfrac{25}{20}\)=\(\dfrac{37}{20}\)

\(\dfrac{9}{27}\)=\(\dfrac{9:9}{27:9}\)=\(\dfrac{1}{3}\) ; \(\dfrac{15}{20}\)=\(\dfrac{15:5}{20:5}\)=\(\dfrac{3}{4}\)

Vậy \(\dfrac{1}{3}\)+\(\dfrac{3}{4}\)=\(\dfrac{4}{12}\)+\(\dfrac{9}{12}\)=\(\dfrac{13}{12}\)