y x 10 =1000
Điền vào ô trống:
x | 5 | –18 | –25 | |
y | –7 | 10 | –10 | |
x . y | –180 | –1000 |
x | 5 | –18 | 18 | –25 |
y | –7 | 10 | –10 | 40 |
x . y | -35 | -180 | –180 | –1000 |
+ x = 5, y = –7 thì x . y = 5. ( –7) = – (5 . 7) = –35.
+ x = –18, y = 10 thì x . y = (–18) . 10 = – (18 . 10) = –180.
+ y = –10 ; x.y = x . (–10) = – (x.10) = – 180, do đó x . 10 = 180 nên x = 18.
+ x = –25; x.y = (–25).y = –(25.y) = –1000, do đó 25.y = 1000 nên y = 40.
1 + 2 + 3 + 4 + 5 + ................................................................... + 1000 = X
1 + 3 + 5 + 7 + 9 + ................................................................... + 999 = Y
1 + 4 + 7 + 10 + 13 + ............................................................... + 1000 = Z
X + Y + Z = ?
theo mik b vận dụng công thức khoảng cách cách đều ấy
Tìm x,y:\(2004 = | x − 4 | + | x − 10 | + | x + 101| + | x + 990 | + | x + 1000 |\)
Tìm y biết: 2020 - y : 8 x 10 = 1000
Tìm y biết:
2020 - y : 8 x 10 = 1000
y : 8 x 10 = 2000 - 1000
y : 8 x 10 = 1000
y : 8 = 1000 : 10
y : 8 = 100
y = 100 x 8
y = 800
Vậy y = 800
\(2020-y:8\times10=1000\)
\(2020-y:80=1000\)
\(y:80=2020-1000\)
\(y:80=1020\)
\(y=1020\times80\)
\(y=81600\)
2020-y:8=1000:10
2020-y:8=100
2020-y=100x8
2020-y=800
y=2020-800=1220
tìm x,y,z biết |x-1000 | + |x-2018 |+ |x-2019 |+ |y-10 |+ |z-1 |=1019
ta có:\(\left|x-1000\right|+\left|x-2019\right|=\left|-x+1000\right|+\left|x-2019\right|\)
\(\ge\left|-x+1000+x-2019\right|=1019\)
dấu = xảy ra khi \(\left(-x+1000\right).\left(x-2019\right)\ge0\)
\(\Rightarrow1000\le x\le2019\)
\(\hept{\begin{cases}\left|x-2018\right|\ge0\\\left|y-10\right|\ge0\\\left|z-1\right|\ge0\end{cases}}\text{dấu = xảy ra khi }\hept{\begin{cases}x=2018\\y=10\\z=1\end{cases}}\)
Vậy để \(\left|x-1000\right|+\left|x-2018\right|+\left|x-2019\right|+\left|y-10\right|+\left|z-1\right|=1019\) => \(\hept{\begin{cases}x=2018\\y=10\\z=1\end{cases}}\)
1) Tính :
a)(1000-1^3)(1000-2^3)(1000-3^3)....(1000-2^2018)
2)Tìm x , biết :
\(\dfrac{27}{3^x}\)=3
3) Tìm x, y biết :
a)\(x^2\)+\(\left(y-\dfrac{1}{10}\right)^{2018}\)=0
b)\(\left(\dfrac{1}{2}x-5\right)^{20}\)+\(\left(y^2-\dfrac{1}{4}\right)^{10}\)\(\le\)0
\(x^2+\left(y-\dfrac{1}{10}\right)^{2018}=0\\ \Leftrightarrow x^2+\left[\left(y-\dfrac{1}{10}\right)^{1009}\right]^2=0\\ \Leftrightarrow\left[{}\begin{matrix}x^2=0\\\left(y-\dfrac{1}{10}\right)^{1009}=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=0\\y=\dfrac{1}{10}\end{matrix}\right.\)
A=|2x-6|-|y+2|+1000
B=|x-1|+|x-2|+3
C=10-|y+3|-|x+5|
Cho x, y, z là các số thoả mãn:
\(\left\{{}\begin{matrix}\dfrac{x}{3}+\dfrac{y}{12}-\dfrac{z}{4}=1\\\dfrac{x}{10}+\dfrac{y}{5}+\dfrac{z}{3}=1\end{matrix}\right.\)
Tính \(M=x^{10}+y^{100}+z^{1000}\)
1. Tính nhẩm:
a ) 18 x 10 =
18 x 100 =
18 x 1000 =
82 x 100 =
75 x 1000 =
19 x 10 =
256 x 1000 =
302 x 10 =
400 x 100 =
b ) 9000 : 10 =
9000 : 100 =
9000 : 1000 =
6800 : 100 =
420 : 10 =
2000 : 1000 =
20020 : 10 =
200200 : 100 =
2002000 : 1000 =
a ) 18 x 10 = 180
18 x 100 = 1800
18 x 1000 = 18000
82 x 100 = 8200
75 x 1000 = 75000
19 x 10 = 190
256 x 1000 = 256000
302 x 10 = 3020
400 x 100 = 40000
b ) 9000 : 10 = 900
9000 : 100 = 90
9000 : 1000 = 9
6800 : 100 = 68
420 : 10 = 42
2000 : 1000 = 2
20020 : 10 = 2002
200200 : 100 = 2002
2002000 : 1000 = 2002
a)18 x 10 = 180
18 x 100 = 1 800
18 x 1000 = 18 000
82 x 100 = 8 200
75 x 1000 = 75 000
19 x 10 = 190
256 x 1000 = 256 000
302 x 10 = 3 020
400 x 100 = 40 000
b)9000 : 10 = 900
9000 : 100 = 90
9000 : 1000 = 9
6800 : 100 = 68
420 : 10 = 42
2000 : 1000 = 2
20 020 : 10 = 2 002
200 200 : 100 = 2 002
2 002 000 : 1000 = 2 002
a) 18*10=180 b)9000:10=900
18*100=1800 9000:100=90
18*1000=18000 9000:1000=9
82*100=8200 6800:100=68
75*1000=75000 420:10=42
19*10=190 2000:1000=2
256*1000=256000 20020:10=2002
302*10=3020 200200:100=2002
400*100=40000 2002000:1000=2002