3- 32/35

= 3/1-32/35

= 105/35 - 32/35

= 73/35

73/35

3 - \(\dfrac{4}{7}\) x \(\dfrac{8}{5}\) 

= 3 - \(\dfrac{32}{35}\)

= \(\dfrac{105}{35}\) - \(\dfrac{32}{35}\) 

= \(\dfrac{73}{35}\) 

5/7 + 4/9 = 73/63

4/5 - 2/3 = 2/15

9/11 + 3/8 = 105/88

16/25 - 2/5 = 6/25.

5/8 x 6 + 1/3 = 15/4 + 1/3 = 49/12

5/4- 1/3 = 15/12 - 4/12 = 11/12

a) = 15/4 + 1/3 = 49/12

b) = 5/4 - 1/3 = 11/12

\(2\left(x-5\right)+3\left(2-3x\right)=5x+7\)

\(\Leftrightarrow2x-10+6-9x=5x+7\)

\(\Leftrightarrow\left(2x-9x\right)+\left(6-10\right)=5x+7\)

\(\Leftrightarrow-7x-4=5x+7\)

\(\Leftrightarrow-7x-5x=4+7\)

\(\Leftrightarrow-12x=11\)

\(\Leftrightarrow x=\frac{-11}{12}\)

\(3x-5\left(x-2\right)+7=4x-12\)

\(\Leftrightarrow3x-5x-10+7=4x-12\)

\(\Leftrightarrow\left(3x-5x\right)-\left(10-7\right)=4x-12\)

\(\Leftrightarrow-2x-3=4x-12\)

\(\Leftrightarrow-2x-4x=3-12\)

\(\Leftrightarrow-6x=-15\)

\(\Leftrightarrow x=\frac{-15}{-6}=\frac{5}{2}\)

\(\frac{1}{5.8}+\frac{1}{8.11}+...+\frac{1}{x\left(x+3\right)}=\frac{101}{1540}\)

\(\Leftrightarrow\frac{3}{5.8}+\frac{3}{8.11}+...+\frac{3}{x\left(x+3\right)}=\frac{101}{1540}.3\)

\(\Leftrightarrow\frac{1}{5}-\frac{1}{8}+\frac{1}{8}-\frac{1}{11}+...+\frac{1}{x}-\frac{1}{x+3}=\frac{303}{1540}\)

\(\Leftrightarrow\frac{1}{5}-\frac{1}{x+3}=\frac{303}{1540}\)

\(\Leftrightarrow\frac{5}{5\left(x+3\right)}=\frac{1}{5}-\frac{303}{1540}\)

\(\Leftrightarrow\frac{5}{5x+15}=\frac{308}{1540}-\frac{303}{1540}\)

\(\Leftrightarrow\frac{5}{5x+15}=\frac{5}{1540}\)

\(\Leftrightarrow5x+15=1540\)

\(\Leftrightarrow5x=1540-15\)

\(\Leftrightarrow5x=1525\)

\(\Leftrightarrow x=1525\div5\)

\(\Leftrightarrow x=305\)

a, S = 1 + 2 - 3 - 4 +5 +6 - 7 - 8 +..... +1998 -1999 -2000 +2001 
=> S = (1-3)+(2-4)+(5-7)+(6-8)+...+(1997-1999)+... + 2001 ( có 1000 hiệu = -2 ) 
=> S = -2 x 1000 + 2001 = 1 

b, S = 1 - 3 + 5 - 7 + 9 - .... - 1999 + 2001 
=> S = (1-3)+(5-7)+(9-11)+....+(1997-1999) + 2001( có 500 hiệu = -2 ) 
=> S = -2 x 500 + 2001 = 1001 

mình chỉ lmf dc 2 câu đầu thông cảm nha

3- 32/ 35

= 3/1- 32/35

= 105/35- 32/35

= 73/35

8/12 + 9/12 = 17/12

12/15 - 5/15 = 7/15

4 x 8/3 = 32/3

1/8 x 3 = 3/8

5 x 2 = 10

2/5 x 1/4 = 2/20 = 1/10

\(\dfrac{2}{3}+\dfrac{3}{4}=\dfrac{8}{12}+\dfrac{9}{12}=\dfrac{17}{12};\dfrac{4}{5}-\dfrac{1}{3}=\dfrac{12}{15}-\dfrac{5}{15}=\dfrac{7}{15}\\ 4\times\dfrac{8}{3}=\dfrac{32}{3};\dfrac{1}{8}\times3=\dfrac{3}{8}\\ 5:\dfrac{1}{2}=5\times\dfrac{2}{1}=10;\dfrac{2}{5}:4=\dfrac{2}{5}\times\dfrac{1}{4}=\dfrac{2}{20}=\dfrac{1}{10}\)

5/6+1/6=1

3-32/35=73/35

gold dragon đây bn

5/6+3/8:9/4= 5/6 + 1/6= 6/6= 1

3-4/7x8/5= 3- 32/35= 3/1-32/35= 73/35

\(4\Omega6=4+5+6+7+8+9=39\)