tim x biet:4/11<x/20<5/11
tim x biet 2.|x+2|+|4-x|=11
tim x biet √x-2 + √4-x =x^2 -6x +11
tim x, y thuoc Z biet
(2x-1)*(y+4)=11
\(\left(2x-1\right).\left(y+4\right)=11\)
\(\Rightarrow2x-1;y+4\) là ước của 11
Ta có bảng :
2x-1 | 1 | 11 | -1 | -11 |
y+4 | 11 | 1 | -11 | -1 |
x | 1 | 6 | 0 | -5 |
y | 7 | -3 | -15 | -5 |
Vậy \(\left(x,y\right)\in\left\{\left(1;7\right),\left(6;-3\right),\left(0;-15\right),\left(-5;-5\right)\right\}\)
(2x-1).(y+4)=11
=> 2x-1 và y+4 thuộc Ư(11) = {-1;-11;1;11}
ta có bảng sau :
2x-1 | -1 | -11 | 1 | 11 |
y+4 | -11 | -1 | 11 | 1 |
x | 0 | -5 | 1 | 6 |
y | -15 | -5 | 7 | -3 |
vậy ta có các cặp số x;y là :
x = 0 ; y = -15
x = -5 ; y = -5
x = 1 ; y = 7
x = 6 ; y = - 3
tim x;y;z biet |x+3/7|+ |y-4/9|+ |z+5/11|=0
|x+3/7|+|y-4/9|+|z+5/11|=0
<=>|x+3/7|=|y-4/9|=|z+5/11|=0
+)x+3/7=0=>x=-3/7
+)y-4/9=0=>y=4/9
+)z+5/11=0=>z=-5/11
Tim so nguyen x , biet : 1 phan 6 = x phan 18 ; x phan 8 = -1 phan 4 ; 4 phan -5 = x phan 10 ; 11 phan 5 = -22 phan x ; x phan 8 = 8 phan x ; x phan -11 = -11 phan x
\(\frac{1}{6}=\frac{x}{18}\Rightarrow x=3\)
\(\frac{x}{8}=-\frac{1}{4}\Rightarrow x=-2\)
\(\frac{4}{-5}=\frac{x}{10}\Rightarrow x=-8\)
\(\frac{11}{5}=-\frac{22}{x}\Rightarrow x=-10\)
\(\frac{x}{8}=\frac{8}{x}\Rightarrow x^2=64\Rightarrow x=8\)
\(\frac{x}{-11}=-\frac{11}{x}\Rightarrow x^2=121\Rightarrow x=11\)
#H
tim x biet 2.|x+2|+|4-x|=11
các bạn giúp mình tí nha đang cần gấp
Tim x biet 11*(x-6)=4x+11
\(11\cdot\left(x-6\right)=4x+11\)
\(11x-66=4x+11\)
\(11x-4x=11+66\)
\(7x=77\)
\(\Rightarrow x=11\)
\(11.\left(x-6\right)=4x+11\)
=) \(11x-66=4x+11\)
=) \(11x-4x=11+66\)
=) \(7x=77\)
=) \(x=77:7=11\)
11.(x-6)=4x+11
11.x-66=4x+11
7x=66+11
7x=77
x=11
vậy x=11
tim x biet : (11/12+11/12.23+11/23.24+...+11/89.100) + x = 2/3
Tim x biet (x-3) + (x-2) + (x-1) + ... + 10 + 11 = 11