Tìm x
I x - 1 I = 0
-13 . I x I = - 26
Bài 3: Tìm x
1) -16 + 23 + x = - 16 2) 2x – 35 = 15 3) 3x + 17 = 12 4) │x - 1│= 0 5) -13 .│x│ = -261.
-16+23+x=-16
<=>7+x=-16
<=>x=-16-7
<=>x=-23
Vậy...
2.
2x – 35 = 15
<=>2x=50
<=>x=25
Vậy...
3.
3x + 17 = 12
<=>3x=-5
<=>x=-5/3
Vậy...
4.
│x - 1│= 0
<=>x-1=0
<=>x=1
Vậy..
5.
-13 .│x│ = -26
<=>IxI=2
<=>x=-2 và x=2
Vậy..
1. Tìm a thuộc Z
a) ( -15 + I a I ) - 30 = -26
b) I -15 +a I -30= -26
c) - IaI +21=45+ (-16)
2.Tìm x thuộc Z
I x+1 I - I x-3 I = 0
ai nhanh tay mk tick cho
Câu 1 : Tính : 13×(12-29)-12×(13-29)
Câu 2: Tìm số nguyên x biết :
A/ x - 2 =-1
B/ -13 × |x| = -26
C/ ( x -1 ) + (x - 3 ) + (x - 5 ) + ( x -7 ) + ( x - 9 ) = 0
Câu 1:
13*(12-29)-12*(13-29)
=13*12-13*29-12*13+12*29
=-13*29+12*29
=29(-13+12)=29*(-1)=-29
Câu 2:
a) x-2=-1
hay x=1
Vậy: x=1
b) \(-13\cdot\left|x\right|=-26\)
\(\Leftrightarrow\left|x\right|=\frac{-26}{-13}=2\)
\(\Leftrightarrow x\in\left\{2;-2\right\}\)
Vậy: \(x\in\left\{2;-2\right\}\)
c) (x-1)+(x-3)+(x-5)+(x-7)+(x-9)=0
\(\Leftrightarrow x-1+x-3+x-5+x-7+x-9=0\)
\(\Leftrightarrow5x-25=0\)
\(\Leftrightarrow5x=25\)
hay x=5
Vậy: x=5
Câu 1 : Tính : 13 . (12 - 29) - 12 . (13 - 29)
13 . (12 - 29) - 12 . (13 - 29)
= (13 . 12 - 13 . 29) - (12 . 13 - 12 . 29)
= 13 . 12 - 13 . 29 - 12 . 13 + 12 . 29
= (13 . 12 - 12 . 13) + (12 . 29 - 13 . 29)
= (13 . 12 - 12 . 13) + 29 . (12 - 13)
= 0 + 29 . (-1)
= 29 . (-1)
= -29
Câu 2: Tìm số nguyên x biết :
A/ x - 2 = -1
x = (-1) + 2
x = 1
B/ -13 . |x| = -26
|x| = (-26) : (-13)
|x| = 2
x = 2 hay x = -2
C/ ( x - 1 ) + (x - 3 ) + (x - 5 ) + ( x - 7 ) + ( x - 9 ) = 0
x - 1 + x - 3 + x - 5 + x - 7 + x - 9 = 0
(x + x + x + x + x) + [(-1) + (-3) + (-5) + (-7) + (-9)] = 0
5x + (-25) = 0
5x = 0 + 25
5x = 25
x = 25 : 5
x = 5
Bài 1: chứng minh: 10n -1 chia hết cho 13 thì 102n-1 chia hết cho 13
Bài 2:tìm x \(\in\)Z
1, I x-8 I + I y+2 I =2
2,I x I - I4-5x I =12 (với x<0)
Tìm số nguyên x
a) 4 + x = 7
b) x + ( -5 ) = -18
c) ( -14 ) + x -7 = -10
d) ( -12 ) - x - ( -19 ) = 0
e) 3 - x = 15 - ( -5 )
f) - x - 14 + 32 = -26
g) x + ( -31 ) - ( -42 ) = -45
h) ( -12 ) - ( 13 - x ) = -15 - ( -17 )
ơ, cái ***, bài này cug đăng à
Bài này dể mà bạn
a) 4 + x = 7
x=7-4
x=3
b) x + ( -5 ) = -18
x=-18-(-5)
x=-13
c) ( -14 ) + x -7 = -10
x=-10+7+14
x=11
d) ( -12 ) - x - ( -19 ) = 0
(-12)-x=0+(-19)
(-12)-x=-19
-x=-19-(-12)
-x=-7
x=7
e) 3 - x = 15 - ( -5 )
3-x=20
x=3-20
x=-17
f) - x - 14 + 32 = -26
-x-14=-26-32
-x-14=-58
-x=-58+14
-x=-44
x=44
g) x + ( -31 ) - ( -42 ) = -45
x-31+42=-45
x=-45-42+32
x=-55
h) ( -12 ) - ( 13 - x ) = -15 - ( -17 )
(-12)-(-13-x)=2
-13-x=-12-2
-13-x=-14
-x=-14+13
-x=-1
x=1
a,I x + 25 I + I - y + 5 I = 0
b,I 6 - 2x I + I x - 13 I = 0
c, I x I + I y I = 1
Tim x va y thuoc Z
tìm x
a, (-1)+3+(-5)+7+(-9)+...+x=600
b, 3.(2-x)+5.(x-6)=-98
c, (x+7).(x+8)=0
d, (x-5)(x2-9)=0
e,(/x/+2).(6-2/x/)=0
f,x.y=-26
m. (2x-1).(y-4)=-13
i (5x+1).(y-1)=4
\(c.\left(x+7\right).\left(x+8\right)=0\)
\(=>x+7=0\)hoặc \(x+8=0\)
\(=>x=0-7=-7\)hoặc \(x=0-8=-8\)
Vậy x = -7 hoặc-8
Tim so nguyen x biet:
a,x-(-24)=3
b,(x+5)-(x-9)=x+3
c,c(x+2)=0
d,(x-1)^2=0
e,x^2-3x=0
f,-13-(6-|x+1|)=24
g,26-|x+9|=-13
i,(3x-6).3=3^4
tìm x
a) I x - 3,5 I =7,5
b) I x + 4/5 I - 1/2 = 0
c) 3,6 - I x - 0,4 I = 0
d) I x - 3,5 I + I 4,5 - x I =0
a) \(\Leftrightarrow\left[{}\begin{matrix}x-3,5=7,5\\x-3,5=-7,5\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=11\\x=-4\end{matrix}\right.\)
b) \(\Leftrightarrow\left|x+\dfrac{4}{5}\right|=\dfrac{1}{2}\)
\(\Leftrightarrow\left[{}\begin{matrix}x+\dfrac{4}{5}=\dfrac{1}{2}\\x+\dfrac{4}{5}=-\dfrac{1}{2}\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-\dfrac{3}{10}\\x=-\dfrac{13}{10}\end{matrix}\right.\)
c) \(\Leftrightarrow\left|x-0,4\right|=3,6\)
\(\Leftrightarrow\left[{}\begin{matrix}x-0,4=3,6\\x-0,4=-3,6\end{matrix}\right.\)\(\Leftrightarrow\left[{}\begin{matrix}x=4\\x=-3,2\end{matrix}\right.\)
d) \(\Leftrightarrow\left\{{}\begin{matrix}x-3,5=0\\4,5-x=0\end{matrix}\right.\)\(\Leftrightarrow\left\{{}\begin{matrix}x=3,5\\x=4,5\end{matrix}\right.\)(vô lý)
Vậy \(S=\varnothing\)