(x+5)+(x+10)+(x+15)+..........+(x+100)=1100
1)Trung bình cộng của các số chia cho 3 dư 2 không vượt quá 2014 là ? 2) (x+5)+(x+10)+(x+15)+(x+20)+...(x+100)=1100
Giải các phương trình:
a) \(\dfrac{x+2001}{5}+\dfrac{x+1999}{7}+\dfrac{x+1997}{9}+\dfrac{x+1995}{11}=-4;\)
b) \(\dfrac{x-15}{100}+\dfrac{x-10}{105}+\dfrac{x-100}{110}=\dfrac{x-100}{15}+\dfrac{x-105}{10}+\dfrac{x-110}{5}.\)
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
123 x 100
12 x 100
1100 + 11
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
Tính giá trị :
a) 100 x 15 + 100 x 95 - 100 x 10
b) 8 : 4 x 5 + 15 - 5
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
\(\dfrac{1100}{x}-\dfrac{1100}{x+5}=2\)
đk : x khác 0 ; -5
\(1100x+5500-1100x=2x\left(x+5\right)\)
\(\Leftrightarrow2x^2+10x-5500=0\Leftrightarrow x=50;x=-55\)(tm)
x + 100 = 1100
tìm x
X + 100 = 1100
X = 1100 - 100
X = 1000
k mk nha thảo
x + 100 = 1100
x = 1100 - 100
x = 1000
=> 1000 + 100
= 1100
\(\dfrac{1100}{x}-\dfrac{1100}{x+5}=2\)
giải pt
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 + 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
(x+5 ) + (x+10 ) + (x+15) + ... +(x+100) = 1110
\(\left(x+5\right)+\left(x+10\right)+\left(x+15\right)+...+\left(x+100\right)=1110\)
\(\Leftrightarrow x+5+x+10+x+15+...+x+100=1110\)
\(\Leftrightarrow20x+\left(5+10+15+...+100\right)=1110\)
\(\Leftrightarrow20x+\frac{\left(100+5\right)\left[\left(100-5\right)\div5+1\right]}{2}=1110\)
\(\Leftrightarrow20x+\frac{2100}{2}=1110\)
\(\Leftrightarrow20x+1050=1110\)
\(\Leftrightarrow20x=1110-1050\)
\(\Leftrightarrow20x=60\)
\(\Leftrightarrow x=60\div20\)
\(\Leftrightarrow x=3\)
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 ...