(x-1)+(x-2)+....+(x-10)=165
<=> (x+x+x+...+x)-(1+2+...+10)=165
<=> 10x - 55 = 165
10x = 165 + 55
10x = 220
x = 220:10
x = 22
(x-1)+(x-2)+....+(x-10)=165
<=> (x+x+x+...+x)-(1+2+...+10)=165
<=> 10x - 55 = 165
10x = 165 + 55
10x = 220
x = 220:10
x = 22
(x-1)+(x-2)+...+(x-10)=165
Tìm y : (y+1) x(y+2) x ......x (y+10)=165
Tìm X :
1) 4 ( 2X - 1 ) \(^2\) - 10 = 54
2) 5 . ( 3 \(^{2X-1}\) + 30 ) = 165
1. Tính giá trị bằng cách hợp lý
a, 78 x 121 + 21 x 121 + 121
b, 24 x 76 + 48 x 12 - 20 x 100
c, ( 165 x 99 + 165 ) - ( 163 x 101 - 163 )
d, 24 x 62 + 48 x 19
2. Tính giá trị của biểu thức
a, 45607 + 847 x 25 - 10750
b, 5625 : 45 + 56807 - 17085
c, ( 2568 - 1464 ) : 48 + 5964
d, 17280 : ( 292 + 668 ) + 1296
3. Thực hiện phéptính
a, 17 x 131 + 69 x 17
b, 13 x 75 + 13 x 25 - 140
c, 204 - 84 : 12
d, 164 x 53 + 47 x 164
4. Tính nhanh
a, 135 + 360 + 65 + 40
b, 463 + 318 + 127 + 22
5. Tìm X biết
a, ( X - 34 ) x 15 = 0
b, 18 x ( X - 16 ) = 54
c, ( X - 12 ) : 5 = 12
d, ( 20 - X ) x 5 = 15
1. 210 x 13 + 210 x 65/ 28 x 104
2. ( 1+2 + 3 +.............+ 100) x (12 + 22+ 32+............+ 102) x ( 65 x 111- 13x 15 x 37)
3. 11x322 x 37 - 915 / 2 x 314)2
Help!!!!!!!!!!!!!!
Tìm x:
a) 2(x+3)-3(x-1)=10
b) x(x-1)+2(x-1)=0
Tìm x biết :
a) ( x-1):3=23
b) 12-2(x+5)=-10
c) x-12(x+5)=-10
d) 6-| x| =5
e) 13-x:2=10
f) | 12 -x | -7=5
i) x2 -7=2
k) x3 -4 =-12
m) 7\(⋮\) (x - 3 )
n) 3 \(⋮\) ( 2x+1)
Tìm x biết:
a. 1/3 + 1/6 + 1/12 + ... + 2/x(x+1) = 2001/2003
b. |x + 1| + |x - 2| + |x + 7| = 5x - 10
c. |x2 - 2| + |2 - x2| = 14
+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 \(x\notin\left\{-2;-5;-10;-17\right\}\)