Ta có |x - 15| + |x - 1| = 14
<=> |15 - x| + |x - 1| = 14
mà |15 - x| + |x - 1| \(\le\left|15-x+x-1\right|=14\)
Dấu "=" xảy ra <=> \(\hept{\begin{cases}15-x\ge0\\x-1\ge0\end{cases}\Rightarrow\hept{\begin{cases}x\le15\\x\ge1\end{cases}\Rightarrow}1\le x\le15}\)
Vậy \(1\le x\le15\)
Tim x biet:
\(\frac{x+1}{18}+\frac{x+2}{17}=\frac{x+5}{14}+\frac{x+4}{15}\)
Tim X,
biet 4(18-5x)-12(3x7)=15(2x-16)-6(2+14)
tim x biet 5/4*(x-8)=-5/3(14-1/2)
tim x y z biet x-1/2=y-2/3=z-3/4 biet x-2y+3z=14
a,tim x biet |x-2|+|3-2x|=2x+1
b,tim x,y thuoc Z biet xy+2x-y=5
c, tinh A=(1-1/15)(1-1/21)(1-1/28).....(1-1/210)
Tim x biet
\(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
bai 1 : Tim x biet
l5x-3l-2x=14
biet rang 1^2+2^2+3^2+....+10^2=385.Tim x biet x+10^2+12^2+14^2+...+20^2=2011+1^2+3^2+...+9^2
1 tim x \(2014.\left|x-12\right|+\left(x-12\right)^2=2013.\left|12-x\right|\)\(x\)|
2 chung minh \(8^7-2^{18}⋮14\)
3 tim x,y,z biet 4x=7y=3z va x+y+z=61
4 tim a,b,c biet \(\frac{1}{2}a=\frac{2}{3}b=\frac{3}{4}c\)vs \(a-b=15\)
giup mk nha moi nguoi,lm dc cang nhiu cang tot
