\(37.46+37.54-5^3.2^3\\ =37\left(46+54\right)-125.8\\ =37.100-1000\\ =3700-1000\\ =2700\)

\(37\cdot46+37\cdot54-5^3\cdot2^3\)
\(\Rightarrow37\cdot\left(46+54\right)-125\cdot8\)
\(\Rightarrow37\cdot100-1000\)
\(\Rightarrow3700-1000\)
\(\Rightarrow2700\)

=37.46+37.54-125.8

=37(46+54)-1000

=37.100-1000

=2700

\(\dfrac{7}{13}\)

\(\dfrac{7}{13}\)

\(\dfrac{7}{13}\)

Số tuổi của mẹ hiện nay là :

24 : (3-1)^3=36(tuổi)

Vậy số tuổi của mẹ là 36 tuổi

a: 3/5=9/15

7/3=35/15

b: 9/10=36/40

5/4=50/40

c: 2/7=8/28

5/4=35/28

d: 8/9=16/18

11/6=33/18

e: 6/5=48/40

13/8=65/40

g: 4/5=8/10

3/2=15/10

h: 5/12=10/24

7/8=21/24

i: 11/4=33/12

13/6=26/12

Bài 2:

\(a,\dfrac{2\times6\times13}{5\times13\times6}=\dfrac{2}{5}\\ b,\dfrac{8\times11\times13}{11\times13\times16}=\dfrac{8}{16}=\dfrac{8}{8\times2}=\dfrac{1}{2}\\ c,\dfrac{5\times18\times12}{15\times24\times16}=\dfrac{5\times3\times3\times6\times3\times4}{3\times5\times4\times6\times4\times4}=\dfrac{3\times3}{4\times4}=\dfrac{9}{16}\\ d,\dfrac{15\times8\times4}{32\times3\times5}=\dfrac{5\times3\times8\times4}{4\times8\times3\times5}=\dfrac{1}{1}=1\)

Bài 1:

\(a,\dfrac{8}{12}=\dfrac{8:4}{12:4}=\dfrac{2}{3}\\ \dfrac{20}{48}=\dfrac{20:4}{48:4}=\dfrac{5}{12}\\ \dfrac{74}{100}=\dfrac{74:2}{100:2}=\dfrac{37}{50}\\ \dfrac{18}{21}=\dfrac{18:3}{21:3}=\dfrac{6}{7}\\ \dfrac{40}{54}=\dfrac{40:2}{54:2}=\dfrac{20}{27}\\ \dfrac{30}{45}=\dfrac{30:15}{45:3}=\dfrac{2}{3}\\ b,\dfrac{18}{24}=\dfrac{18:6}{24:6}=\dfrac{3}{4}\\ \dfrac{49}{28}=\dfrac{49:7}{28:7}=\dfrac{7}{4}\\ \dfrac{15}{35}=\dfrac{15:5}{35:5}=\dfrac{3}{7}\\ \dfrac{28}{40}=\dfrac{28:4}{40:4}=\dfrac{7}{10}\\ \dfrac{36}{27}=\dfrac{36:9}{27:9}=\dfrac{4}{3}\\ \dfrac{56}{49}=\dfrac{56:7}{49:7}=\dfrac{8}{7}\)

\(c,\dfrac{85}{51}=\dfrac{85:17}{51:17}=\dfrac{5}{3}\\ \dfrac{1515}{2323}=\dfrac{1515:101}{2323:101}=\dfrac{15}{23}\\ \dfrac{39}{26}=\dfrac{39:13}{26:13}=\dfrac{3}{2}\\ \dfrac{323232}{515151}=\dfrac{323232:10101}{515151:10101}=\dfrac{32}{51}\)

\(\dfrac{2}{3};\dfrac{4}{6}\)

Cíu tui cái coi 

4 phần 6

\(\dfrac{8\times3\times4}{16\times3}\)

\(=\dfrac{8\times3\times2\times2}{8\times2\times3}\)

b) \(\dfrac{30\times25\times7\times8}{75\times8\times12\times14}\)

\(a,3\left(x^2-7\right)-x\left(3x+5\right)=3x^2-21-3x^2-5x=-5x-21\\ b,\left(12x^2y^2-6xy\right):3xy+2y=3xy\left(4xy-2\right):3xy+2y=4xy-2+2y\)

\(c,\dfrac{4}{x+1}+\dfrac{8}{\left(x-1\right)\left(x+1\right)}=\dfrac{4\left(x-1\right)+8}{\left(x-1\right)\left(x+1\right)}=\dfrac{4x-4+8}{\left(x-1\right)\left(x+1\right)}=\dfrac{4x+4}{\left(x-1\right)\left(x+1\right)}=\dfrac{4\left(x+1\right)}{\left(x-1\right)\left(x+1\right)}=\dfrac{4}{x-1}\)

1 chữ đó là chữ  N