a) -2x - (x-17) = 34-(-x + 25)
-2x- x+17= 34+x-25
-2x-x-x= -17 +34-25
-4x = -8
x = 2
b)17x-(-16x-27) = 2x+43
17x + 16x + 27 = 2x + 43
17x + 16x -2x= -27 +43
31x= 26
x= 21/31
c)- 2x- 3(x-17) = 34- 2(-x + 25)
-2x - 3x + 51 = 34 + 2x -50
-2x - 3x -2x = -51 + 34 -50
-7x = -67
x = 67/7
d) 17x +3(-16x-37) = 2x+ 43 -4x
17x -48x -111 = 2x + 43 -4x
17x - 48x -2x + 4x = 111 -43
-29x = 68
x = -68/29
Tìm số nguyên x
1/ \(17x+3\left(-16x-37\right)=2x+43-4x\)
2/ \(-2x-3\left(x-17\right)=34-2\left(-x+25\right)\)
3/ \(\left\{-3x+2\left[45-x-3\left(3x+7\right)-2x\right]+4x\right\}=55-103-57:\left[-2\left(2x-1\right)^2-\left(-9\right)^0\right]=-106\)
4/ \(-2x+3\left\{12-2\left[3x-\left(20+2x\right)-4x\right]+1\right\}=45\)
5/ \(3x-32>-5+1\)
6/ \(15+4x< 2x-145\)
7/ \(-3\left(2x+5\right)-16< -4\left(3-2x\right)\)
8/ \(-2x+15< 3x-7< 19-x\)
Bài 1 . Tính ( tính nhanh nếu có thể )
a. 31.72 - 31.70 - 31.2
b. 25. ( 32 + 47 ) - 32. ( 25 + 47 )
c. [ 3. ( - 2 ) - ( - 8 ) ] . ( - 7 ) - ( - 2 ) . ( - 5 )
d. ( - 3 ) ^ 2 + 3 ^ 3 - ( - 3 ) ^ 0
Bài 2 . Tìm x biết
a. - 2x - 3 = 15
b. 5 - 4x = 17
c. - 2 | x - 3 | = 16 : ( - 2 )
d. ( x - 1) ^ 2 = 4
Bài 3. Tìm GTNN của A = | x - 2017 | + ( y - 1 ) ^ 2018 + 2017
Bài 4. Chứng tỏ : ( 43 ^ 43 - 17 ^ 17 ) chia hết cho 2
Bài 5. Chứng tỏ : ( 52 ^ 52 - 13 ^ 52 ) chia hết cho 5
Tim x
A, 2x - ( x + 25 ) - 75 = -12
B, ( x - 12 ) - 15 = ( 120 - 18 ) - (20 + x )
C, 17 - { - x - [ - x - ( - x )] } = -16
D, x - { [ - x + ( x +3 ) ] - [ ( x +3) - ( x - 2) ] }= 0
Tìm số nguyên x:
1.x-43=(35-x)-48
2.305-x+14=48+(x-23)
3.-(x-6+85)=(x+51)-54
4.-(35-x)-(37-x)=33-x
5.13-|x|=|-4|
6.|x|-3+6=16
7.35-|2x-1|=14
8.|3x-2|+5=9-x
9.x-(-25+7)>12-(15-14)
10.|17+(x-15)|<5
+Tim x :
a ) \(\left(x-\frac{1}{2}\right)^3=\frac{1}{27}\)
b )\(\left(x+\frac{1}{2}\right)^2=\frac{4}{25}\)
c ) \(\left(x+1\right)^{x+2}=\left(x-1\right)^{x+6}\) (x ϵ Z )
d ) \(\left(2x+3\right)^{2016}=\left(2x+3\right)^{2018}\)
e ) \(\frac{3}{x+2.x+5}+\frac{5}{x+5.x+10}+\frac{7}{x+10.x+17}=\frac{x}{x+2.x+17}\) Với \(x\notin\left\{-2;-5;-10;-17\right\}\)
tìm x biết :
a) \(\left(x+\frac{1}{5}\right)^2+\frac{17}{25}=\frac{26}{25}\)
b) \(-1\frac{5}{27}-\left(3x-\frac{7}{9}\right)^3=-\frac{24}{27}\)
c) \(\left(x+\frac{1}{2}\right).\left(\frac{2}{3}-2x\right)=0\)
Tìm GTLN hoặc GTNN của :
a) \(A=\left|-x+8\right|-21\)
b) \(B=\left|-x-17\right|+\left|y-36\right|+12\)
c) \(C=-\left|2x-8\right|-35\)
d) \(D=3\left(3x-12\right)^2-37\)
e) \(E=-21-3\left|2x+50\right|\)
g) \(G=\left(x-3\right)^2+\left|x^2-9\right|+25\)
tim STN x biet
a, 21 thuoc B(x-3)
b, 1-x thuoc U(17)
c, 2x+3 thuoc B(2x-1)
d, x+1 thuoc U(x mu 2+x+3)
e, 3x+1:11-2x
1. Tìm x , biết :
a, x-3 + (5+3) = 3-(6-4)
b, 3-(x-6)+(2x-4)=11
c, 17-(2-x)-(3-x-17)=6
2. Rút gọn phép tính :
a, a-(b-c)+(a-c+b)-b
b, 2x -(5-x+a)+(x-5-a)
