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8 tháng 5 2022

vì 48⋮5x-1 ⇒5x-1ϵ Ư(48)={48; -48; 2; -2 ; 4; -4; 8;-8;12;-12;24;-24}

5X-1 48 -48 2 -2 4 -4 8 -8 12 -12 24 -24
5X 49 -47 3 -1 5 -3 9 -7 13 -11 25 -23
X 49/5 -47/5 3/5 -1/5 1 -3/5 9/5 -7/5 13/5 -11/5 5 -23/5

 

8 tháng 5 2022

Vì  48 ⋮ 5x-1 ⇒ 5x-1 ϵ Ư(48)= {48; -48; 2; -2 ; 4; -4; 8;-8;12;-12;24;-24}

5X-1  48 -48 2 -2 4 -4 8 -8 12 -12 24 -24
5X 49 -47 3 -1 5 -3 9 -7 13 -11 25 -23
=>X 49/5 -47/5 3/5 -1/5 1 -3/5 9/5 -7/5 13/5 -11/5 5 -23/5
30 tháng 11 2018

a, \(\dfrac{4x+13}{5x\left(x-7\right)}-\dfrac{x-48}{5x\left(7-x\right)}\)

\(=\dfrac{4x+13}{5x\left(x-7\right)}+\dfrac{x-48}{5x\left(x-7\right)}\)

\(=\dfrac{4x+13+x-48}{5x\left(x-7\right)}\)

\(=\dfrac{5x-35}{5x\left(x-7\right)}\)

\(=\dfrac{5\left(x-7\right)}{5x\left(x-7\right)}=\dfrac{1}{x}\)

b, \(\dfrac{1}{x-5x^2}-\dfrac{25x-15}{25x^2-1}\)

\(=\dfrac{1}{x\left(1-5x\right)}+\dfrac{25x-15}{\left(1-5x\right)\left(1+5x\right)}\)

\(=\dfrac{1+5x}{x\left(x-5x\right)\left(1+5x\right)}+\dfrac{x\left(25x-15\right)}{x\left(1-5x\right)\left(1+5x\right)}\)

\(=\dfrac{1+5x+25x^2-15x}{x\left(1-5x\right)\left(1+5x\right)}\)\(=\dfrac{25x^2-10x+1}{x\left(1-5x\right)\left(1+5x\right)}=\dfrac{\left(5x-1\right)^2}{x.\left(1-5x\right)\left(1+5x\right)}\)

\(=\dfrac{\left(5x-1\right)^2}{-x\left(5x-1\right)\left(1+5x\right)}\) \(=\dfrac{-\left(5x-1\right)}{x\left(1+5x\right)}\)

9 tháng 2 2018

Đáp án B

1 tháng 3 2017

a) ( -48 ) + 48 . ( -78 ) + 48 . ( -24 )

=      48 . ( -1 - 78 - 24 )

=      48 .     ( -103 )

=           -4944

b) 31 . ( -18 ) + 31 . ( -81 ) - 31

=      31 . ( -18 - 81 - 1 )

=      31 .        62

=         -3100

c) 35 x 18 - 5 x 7 x 28 

 =   35 x 18 - 35 x 28

=      35 x ( 18 - 28 )

=      35 x   ( -10 )

=            -350

d) ( -16 ) + 24 + 16 - 34

=  [ ( -16 ) + 16 ] + ( 24 - 34 ) 

=          0           +      ( - 10 )

=                  -10

14 tháng 12 2021

\(=\dfrac{4x+13-x+48}{5x\left(x-7\right)}=\dfrac{3x+61}{5x\left(x-7\right)}\)

9 tháng 2 2021

Ta có : \(\dfrac{5x-150}{50}+\dfrac{5x-102}{49}+\dfrac{5x-56}{48}+\dfrac{5x-12}{47}+\dfrac{5x-660}{46}=0\)

\(\Leftrightarrow\dfrac{5x-150}{50}-1+\dfrac{5x-102}{49}-2+\dfrac{5x-56}{48}-3+\dfrac{5x-12}{47}-4+\dfrac{5x-660}{46}+10=0\)

\(\Leftrightarrow\dfrac{5x-200}{50}+\dfrac{5x-200}{49}+\dfrac{5x-200}{48}+\dfrac{5x-200}{47}+\dfrac{5x-200}{46}=0\)

\(\Leftrightarrow\left(5x-200\right)\left(\dfrac{1}{50}+\dfrac{1}{49}+\dfrac{1}{48}+\dfrac{1}{47}+\dfrac{1}{46}\right)=0\)

\(\Leftrightarrow5x-200=0\)

\(\Leftrightarrow x=40\)

Vậy ...

 

 

 

 

 

 

 

Ta có: \(\dfrac{5x-150}{50}+\dfrac{5x-102}{49}+\dfrac{5x-56}{48}+\dfrac{5x-12}{47}+\dfrac{5x-660}{46}=0\)

\(\Leftrightarrow\dfrac{5x-150}{50}-1+\dfrac{5x-102}{49}-2+\dfrac{5x-56}{48}-3+\dfrac{5x-12}{47}-4+\dfrac{5x-660}{46}+10=0\)

\(\Leftrightarrow\dfrac{5x-200}{50}+\dfrac{5x-200}{49}+\dfrac{5x-200}{48}+\dfrac{5x-200}{47}+\dfrac{5x-200}{46}=0\)

\(\Leftrightarrow\left(5x-200\right)\left(\dfrac{1}{50}+\dfrac{1}{49}+\dfrac{1}{48}+\dfrac{1}{47}+\dfrac{1}{46}\right)=0\)

mà \(\dfrac{1}{50}+\dfrac{1}{49}+\dfrac{1}{48}+\dfrac{1}{47}+\dfrac{1}{46}>0\)

nên 5x-200=0

\(\Leftrightarrow5x=200\)

hay x=40

Vậy: S={40}

21 tháng 12 2021

\(-12x=48\)
\(x=4\)

21 tháng 12 2021

-5x-7x=48

-12x=48

X=48:(-12)

X=(-4)