Sai rồi bạn

a)5x6=30

b)4x7=28

c)3x9=27

d)5x40=200

5+5+5+5+5+5=5×6

4+4+12+8=4×7

3+6+9+12=3×10

30 ; 28;30;200 NHA BN

a) 5 + 5 + 5 + 5 + 5 + 5 = 5.6=30

b) 4 + 4 + 12 + 8 =4.7=28

c) 3 + 6 + 9 + 12 =3.9=27

d) 65 + 93 + 35 + 7 =5.40=200

a) 5+5+5+5+5+5=30

b) 4+4+12+8=28

c) 3+6+9+12=30

d)65+93+35+7=200

Cuối cùng, theo mình nghĩ, bạn là con gái

k mình nha

5+5+5+5+5+5=5x6=30

4+4+12+8=28

3+6+9+12=30

65+93+35+200

Bạn là gái

1

Hồng có nhiều hơn Hà 10 viên bi, nếu Hồng cho Hà 4 viên bi thì Hồng còn nhiều hơn Hà mấy viên bi

Giải: 

Số bi mà Hồng nhiều hơn Hà là:

10 -(4+4) = 2 (viên bi)

2

Viết các tổng sau thành tích:

a) 5 + 5 + 5 + 5 + 5 + 5 =30 

b) 4 + 4 + 12 + 8 =28

c) 3 + 6 + 9 + 12 = 30

d) 65 + 93 + 35 + 7 = 200

1)hồng còn nhiều hơn hà: 2 viên

2)

a)5+5+5+5+5+5=5x6

b)4+4+12+8=4x7

c)3+6+9+12=3x10

d)ko biết làm

\(\left(19\frac{5}{8}:\frac{7}{12}-13\frac{1}{4}:\frac{7}{12}\right).\frac{4}{5}\)

\(=\left(\frac{157}{8}:\frac{7}{12}-\frac{53}{4}:\frac{7}{12}\right).\frac{4}{5}\)

\(=\left[\left(\frac{157}{8}-\frac{53}{4}\right):\frac{7}{12}\right].\frac{4}{5}\)

\(=\left[\frac{51}{8}:\frac{7}{12}\right].\frac{4}{5}\)

\(=\frac{153}{14}.\frac{4}{5}\)

\(=\frac{306}{35}\)

\(\left(\frac{-2}{5}+\frac{3}{7}\right)-\left(\frac{4}{9}+\frac{12}{20}-\frac{13}{35}\right)+\frac{7}{35}\)

\(=\frac{1}{35}-\frac{212}{315}+\frac{7}{35}\)

\(=\frac{1}{35}+\frac{-212}{315}+\frac{7}{35}\)

\(=\frac{9}{315}+\frac{-212}{315}+\frac{63}{315}\)

\(=\frac{-140}{315}=\frac{-4}{9}\)

câu a : 

\(\dfrac{-8}{24}+\dfrac{-4}{12}=\dfrac{-1}{3}+\dfrac{-1}{3}=\dfrac{-2}{3}\)

câu b : 

\(\dfrac{-20}{35}+\dfrac{16}{24}=\dfrac{-4}{7}+\dfrac{2}{3}=\dfrac{2}{21}\)

câu c : 

\(\dfrac{-3}{9}+\dfrac{-6}{15}=\dfrac{-1}{3}+\dfrac{-2}{5}=\dfrac{-11}{15}\)

câu d : 

\(\dfrac{3}{13}-\dfrac{4}{10}=\dfrac{3}{13}-\dfrac{2}{5}=\dfrac{-11}{65}\)

câu e : 

\(\dfrac{5}{17}-\dfrac{9}{15}=\dfrac{5}{17}-\dfrac{3}{5}=\dfrac{-26}{85}\)

câu g : 

\(\dfrac{9}{18}-\dfrac{6}{15}+\dfrac{3}{-9}=\dfrac{9}{18}-\dfrac{6}{15}+\dfrac{-3}{9}\\ =\dfrac{1}{2}-\dfrac{2}{5}+\dfrac{-1}{3}=\dfrac{-7}{30}\)

câu h : 

\(\dfrac{5}{4}-\dfrac{1}{2}+\dfrac{-7}{8}=\dfrac{10}{8}-\dfrac{4}{8}+\dfrac{-7}{8}=\dfrac{-1}{8}\)

c) Ta có: \(\dfrac{3}{5}+\dfrac{-5}{20}+\dfrac{30}{75}+\dfrac{-7}{4}\)

\(=\dfrac{3}{5}+\dfrac{2}{5}+\dfrac{-1}{4}+\dfrac{-7}{4}\)

\(=1-2=-1\)

Giải:

a)-1/12+4/3=-1/12+16/12=15/12=5/4

b)(-4/14-3/15)-(1/5-20/35-(-1)).7

=-17/35-22/35.7

=-17/35-22/5

=-171/35

c)3/5+-5/20+30/75+-7/4

=3/5+-1/4+2/5+-7/4

=(3/5+2/5)+(-1/4+-7/4)

=1+-2

=-1

d)5/6.-12/14+7/13

=-5/7+7/13

=-16/91

e)2/-9-5/-36-1/4

=-1/12-1/4

=-1/3

f)2/23+-5/12+7/18+21/23+-7/12

=(2/23+21/23)+(-5/12+-7/12)+7/18

=1+-1+7/18

=7/18