2,5 (nha)

Ai k mình mình k lại

bài 1 thì bạn tự đi mà tính

bài 2

2.5

2, x=2,5

 

a: \(\Leftrightarrow\left(\dfrac{x+2001}{5}+1\right)+\left(\dfrac{x+1999}{7}+1\right)+\left(\dfrac{x+1997}{9}+1\right)+\left(\dfrac{x+1995}{11}+1\right)=0\)

=>x+2006=0

=>x=-2006

b: \(\Leftrightarrow\left(\dfrac{x-15}{100}-1\right)+\left(\dfrac{x-10}{105}-1\right)+\left(\dfrac{x-100}{5}-1\right)=\left(\dfrac{x-100}{15}-1\right)+\left(\dfrac{x-105}{10}-1\right)+\left(\dfrac{x-110}{5}-1\right)\)

=>x-105=0

=>x=105

12300,1200,1111

nha bạn

123 x 100 = 12300

12 x 100 = 1200

1100 + 11 = 1111

hi

123 x 100

= 1230

12 x 100

= 1200

1100 + 11

= 1111

k cho mk nha pạn

a) 100 x 15 + 100 x 95 -100 x10

  = 100 x ( 15 +95 - 10 )

  = 100 x 100

  = 10000

b) 8: 4 x 5 + 15-5

  = 2 x 5 + 15-5 

  = 10+15 -5

  = 25-5

  = 20

a) 100x15+100x95-100x10

=100x(15+95-10)

=100x100

=10000

mik chỉ làm 1 phần thôi nha

k mik nha cac bạn

a) 100 x 15 + 100 x 95 - 100 x 10

= 100 x (15+95-10)

= 100 x 100

= 10000

b) 8 : 4 x 5 + 15 - 5

=2 x5 + 10

=10+10

= 20

đk : x khác 0 ; -5 

\(1100x+5500-1100x=2x\left(x+5\right)\)

\(\Leftrightarrow2x^2+10x-5500=0\Leftrightarrow x=50;x=-55\)(tm) 

= - 55 tm

X + 100 = 1100

      X    = 1100 - 100

      X    = 1000

k mk nha thảo

x+100=1100

x=1100-100

x=1000

x + 100 = 1100

x = 1100 - 100

x = 1000

=> 1000 + 100

= 1100

Pt <=>  \(\dfrac{1}{x}-\dfrac{1}{x+5}=\dfrac{1}{550}\)

<=>  \(\dfrac{\left(x+5\right)-x}{x\left(x+5\right)}=\dfrac{1}{550}\)

<=> \(\dfrac{5}{x\left(x+5\right)}=\dfrac{1}{550}\)

<=> \(x^2+5x=2750\)

<=> \(x^2+5x-2750=0\)

<=> \(\left(x^2+5x+2,5^2\right)-52,5^2=0\) (bước này hơi tắt xíu nha :<)

<=> \(\left(x+2,5\right)^2-52,5^2=0\)

<=> \(\left(x+55\right)\left(x-50\right)=0\)

<=> \(\left[{}\begin{matrix}x+55=0\\x-50=0\end{matrix}\right.\Rightarrow\left[{}\begin{matrix}x=-55\\x=50\end{matrix}\right.\)

Vậy nghiệm của phương trình là x \(\in\left\{-55;50\right\}\)

\(\dfrac{1100}{x}-\dfrac{1100}{x+5}=2\)

\(\dfrac{1100\left(x+5\right)-1100x}{x\left(x+5\right)}=\dfrac{2x\left(x+5\right)}{x\left(x+5\right)}\)

\(1100x+5500-1100x=2x^2+10x\)

\(2x^2+10x-5500=0\)

Δ' \(=5^2-2\left(-5500\right)\)

Δ'\(=11025\)

\(\left[{}\begin{matrix}x=50\\x=-55\end{matrix}\right.\)

x + 100 = 1100

x = 1100 - 100

x = 1000.

Đáp số: x = 1000. 

Tíck cho mìk vs nhá Blood Red Dragon fiery heat!

x+100=1100

x       = 1100 - 100

x       = 1000

    Đáp số: x = 1000

x+100=1100

x=1100-100

x=1000

những người bạn của tôi

\(\left(x+5\right)+\left(x+10\right)+\left(x+15\right)+...+\left(x+100\right)=1110\)

\(\Leftrightarrow x+5+x+10+x+15+...+x+100=1110\)

\(\Leftrightarrow20x+\left(5+10+15+...+100\right)=1110\)

\(\Leftrightarrow20x+\frac{\left(100+5\right)\left[\left(100-5\right)\div5+1\right]}{2}=1110\)

\(\Leftrightarrow20x+\frac{2100}{2}=1110\)

\(\Leftrightarrow20x+1050=1110\)

\(\Leftrightarrow20x=1110-1050\)

\(\Leftrightarrow20x=60\)

\(\Leftrightarrow x=60\div20\)

\(\Leftrightarrow x=3\)

Vậy x = 3

\((x+5)+(x+10)+(x+15)+...+(x+100)=1110\)

\(\Rightarrow x+5+x+10+x+15+...+x+100=1110\)

\(\Rightarrow(x+x+x+...+x)+(5+10+15+...+100)=1110\)

\(\Rightarrow100x+\frac{(5+100)\cdot20}{2}=1110\)

\(\Rightarrow100x+1050=1110\)

\(\Rightarrow100x=1110-1050\)

\(\Rightarrow100x=60\)

....

Ta có (x+5)+(x+10)+(x+15)+....+(x+100)=1110

=>(x×100)+(5+10+15+...+100)=1110

=>(x×100)+ 1050=1110

=> x×100= 1110-1050=60

=>x= 3/5

Vậy ...