[1-1/2}x{1-1/3}x{1-1/4]x.....x{1-11/2016]
tìm x biết
a:x+1/10+x+1/11+x+1/12=x+1/13+x+1/14
b:x+4/2013+x+3/2016=x+2/2015+x+1/2016
a) \(\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}=\frac{x+1}{13}+\frac{x+1}{14}\)
\(\Rightarrow\frac{x+1}{10}+\frac{x+1}{11}+\frac{x+1}{12}-\frac{x+1}{13}-\frac{x+1}{14}=0\)
\(\Rightarrow\left(x+1\right)\left(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\right)=0\)
Vì \(\frac{1}{10}+\frac{1}{11}+\frac{1}{12}-\frac{1}{13}-\frac{1}{14}\ne0\) nên x+1=0
=>x=0-1
=>x-1
a:x+1/10+x+1/11+x+1/12=x+1/13+x+1/14
<=>(x+1)(1/10 + 1/11+1/12) =(x+1)(1/13 + 1/14)
<=>(x+1)(1/10 + 1/11+1/12 -1/13 -1/14)=0
<=> x+1=0(vì biểu thức 1/10 + 1/11 +1/12-1/13-1/14#0)
<=>x= -1
b:hình như sai đề
Tính nhanh
1) 9 x 10 + 10 x 11 + 11 x 12 + ....+ 2015 x 2016
2) 1 x 2 x 3 + 2 x 3 x 4 + 3 x 4 x 5 + ....+ 2015 x 2016 x 2017
1) 9 x 10 + 10 x 11 + 11 x 12 + ....+ 2015 x 2016
=9x10x11-8x9x10+10x11x12-9x10x11+...+2015x2016x2017-2014x2015x2013
=2015x2016x2017-8x9x10
=8193537360
Tính: S = 1 - 2 + 3 - 4+ ... + 197 -198 + 199 -200
Tính: P = (-1) + (-2) + (-3) + .... + (-99) + (-100)
Tìm các số nguyên x, biết:
a) x2 - 1 = -54 - 43 - 32 - (-6971) - (-20170)
b) 7(x-1) < 0 và x > -11
c) -10(x - 2016) - 7(x - 2016) - 6(x-2016) - 4(x -2016) - 3(x - 2016) = -30
3.
a.(4/5 -13/26) : 3/5
b. (3/4 - 11/25) : 8/5
c (1 - 1/7) x (1 - 1/6) x ( 1- 1/25)x .........x (1 - 1/100)
d. (1 - 1/2) x (1 - 1/3) x (1 x 1/4 )x ........x (1 - 1/2016) x (1 - 1/2017)
Nhanh mk tik nhưng nhớ phải đúng!
Tính: ( 1 + 2 + 3 + 4 + 5 +.............+ 2015 + 2016 ) x ( 9 x 11 - 100 + 1 )
\(\left(1+2+3+4+5+......+2015+2016\right)\cdot\left(9\cdot11-100+1\right)\)
\(=\left(1+2+3+4+5+......+2015+2016\right)\cdot\left(99-100+1\right)\)
\(=\left(1+2+3+4+5+......+2015+2016\right)\cdot\left(-1+1\right)\)
\(=\left(1+2+3+4+5+......+2015+2016\right)\cdot0\)
\(=0\)
TÍNH (1 +2 + 3 + 4 + 5 +...+ 2015 + 2016 ) x (9 x 11 - 100 + 1 )
Tta thấy 9x11-100+1=99-100+1
=-1+1=0
Mà số nào nhân với 0 cũng bằng 0 nên đáp án bàng 0 nha bạn
Nhớ ủng hộ mk nha
( 1+2+3+4+5+....+2015+2016) x ( 99-100+1)=( (2016-1):1+1) x 0 = 2016 x 0 = 0
( 1+2+3+4+5+...+2015+2016) x (9x11-100+1)
đặt (1+2+3+...+2015+2016)= A
+) số số hạng của dãy A là:
(2016-1):1+1= 2016
+) Tổng của dãy A là: (2016+1)x2016:2 = 2033136
Tính 9x11-100+1= 99-100+1= 0
=> A x (9x11-100+1)= A x 0 = 0
đáp số: 0
\(A=\left(6:\frac{3}{5}-1\frac{1}{6}x\frac{6}{7}\right):\left(4\frac{1}{5}x\frac{10}{11}+5\frac{2}{11}\right)\)\(B=\left(1-\frac{1}{2}\right)x\left(1-\frac{1}{4}\right)x.......x\left(1-\frac{1}{2015}\right)x\left(1-\frac{1}{2016}\right)\)
\(C=5\frac{9}{10}:\frac{3}{2}-\left(2\frac{1}{3}x4\frac{1}{2}-2x2\frac{1}{3}\right):\frac{7}{4}\)
a)1/2+4/6+1/12+...+1/(x+1).x=2016/2017
b)5/8/17:x+(-4/17):x+3/1/5:17/1/3=4/11
giải hộ mk nha các bn mk sẽ k mk thề
ban vt sai dau bai roi phai la
1/2+1/6+1/12+....+1/(x+1).x=2016/2017
1/1.2+1/2.3+1/3.4+.....+1/x.(x+1)=2016/2017
1-1/2+1/2-1/3+......+1/x-1/x+1=2016/2017
1-1/x+1=2016/2017
1/x+1=1-2016/2017
1/x+1=1/2017
=>x+1=2017
=>x=2016
b)
85/8:x+(-4)/17:x+15:51=4/11
85/8:x+(-4)/17:x=13/187
1413/136:x=13/187
x=15543/104
a, x+1/2013+x+1/2014+x+1/2015=x+1/2016+x+1/2017
b,x-1/2013+x-2/2014+x-3/2015=x-4/2016-2