( x-3 ) ( x-5 ) < 0
\(\Rightarrow\)\(\left\{{}\begin{matrix}x-3< 0\Rightarrow x< 3\\x-5>0\Rightarrow x>5\end{matrix}\right.\)
\(\Rightarrow\) 5 < x < 3
\(\Rightarrow\) x \(\in\) {\(\varnothing\)}
\(\Rightarrow\)\(\left\{{}\begin{matrix}x-3>0\Rightarrow x>3\\x-5< 0\Rightarrow x< 5\end{matrix}\right.\)
\(\Rightarrow\)3 < x < 5
\(\Rightarrow\) x = 4
tim tat ca cac so nguyen a biet 3a+1chia het cho a-1
tim x,biet
5.(3-2x)+5(x-4)=6-4x
tim x biet |5-x|-17=13
Tim X E Z , biet
0<X-1\(\le\)1
tim x thuoc z biet |x | - (-2) = -1
Tim x biet
(x+7) chia hết cho (x+2)
Tim số nguyên x:
1) x2 - 5x = 0
2) | x - 9 | . (-8) = -16
3) | 4 - 5x | = 24 với x bé hơm hoặc bằng 0
4) x . ( x - 2 ) > 0
5) x . ( x - 2 ) < 0
cho cac so tu nhien x,y. biet 3.x+2.y+11 chia het cho 15. Hoi 18.x+2.y+26 co chia het cho 15 khong? Vi sao.
Tìm x, biết :
a) x. (x + 2)= 0
b) (x - 3).( 4 - x )
c) x^2= 2x
d) (x - 5 ). ( x^2 + 1 ) =0
e) -12. ( x - 5 ) + 7 . ( 3 - x )=5
g) 30. ( x +2) + 6. ( x - 5 ) - 24x= 102
h) ( x + 1 ) + (x + 2 ) + ... + ( x + 99) =0
