tim x , biet
(2x-1)^100 = (2x-1)^1000
Tim x biet
1/3×5+1/5×7+.....+1/(2x+1)(2x+3)=100/609
tim x biet : (2x-1)+(4x-1)+...+(400x-200)=5+10+...+100
cho mình sửa đề 1 chút:
Tìm số nguyên x biết: ( 2x - 1) + ( 4x - 2) + ( 6x - 3) + .............+( 400x - 200) = 5 + 10 + 15 + .......+ 1000 .
x = 0
tim x biet: (2x-3)^10x=(3-2x)^100
\(\left(2x-3\right)^{10x}=\left(3-2x\right)^{100}\)
\(\Leftrightarrow\left(2x-3\right)^{10x}=\left(2x-3\right)^{100}\)
\(\Leftrightarrow10x=100\Leftrightarrow x=100:10=10\)
\(\left(2x-3\right)^{10x}=\left(3-2x\right)^{100}\)
\(\Rightarrow\left(2x-3\right)^{10x}=\left(2x-3\right)^{100}\)
\(\Rightarrow10x\Leftrightarrow x=100:10=10\)
~Study well~ :)
a,tim x biet |x-2|+|3-2x|=2x+1
b,tim x,y thuoc Z biet xy+2x-y=5
c, tinh A=(1-1/15)(1-1/21)(1-1/28).....(1-1/210)
tim x biet (2x+1)+(2x+2)+...+(2x+2015)
Tim x biet |2x-1|+|1-2x|=8
tim x biet (2x+1)+(2x+2)+...+(2x+2015)=0
Có 2015 số hạng
Tổng là (2x+1+2x+2015).2015:2=0
4x+2016=0
4x=-2016
x=-504
Ủng hộ mk nha
( 2x + 1 ) + ( 2x + 2 ) + ... + ( 2x + 2015 ) = 0
=> ( 2x + 2x + .. + 2x ) + ( 1 + 2 + ... + 2015 ) = 0
2015 số 2x
=> 2x . 2015 + 2031120 = 0
=> 2x . 2015 = 0 - 2031120
=> 2x . 2015 = - 2031120
=> 2x = ( - 2031120 ) : 2015
=> 2x = - 1008
=> x = ( - 1008 ) : 2
=> x = - 504
=> ( 2x + 2x + .... + 2x + 2x ) + ( 1 + 2 + 3 + .... + 2015 ) = 0
=> ( 2x.2015 ) + { [ 2015.( 2015 + 1 ] : 2 } = 0
=> 4030x + [ ( 2015 . 2016 ) : 2 ] = 0
=> 4030x + ( 4062240 : 2 ) = 0
=> 4030x + 2031120 = 0
=> 4030x = - 2031120
=> x = - 2031120 : 4030 = - 504
Vậy x = - 504
tim x biet (2x+1)+(2x+2)+...+(2x+2015)=0
Có tất cả số 2x là:
(2015-1):1+1=2015(số)
Ta có:(2x+1)+(2x+2)+............+(2x+2015)=0
=>2015*2x+(1+2+3+............+2015)=0
=>4030x+2031120=0
=>4030x=-2031120
=>x=-504
a, Tim x biet:/x-2/+/3-2x/=2x+1
b, Tim x,y thuoc Z biet:xy+2x-y=5
c, tim x,y,z, biet :2x=3y;4y=5zva 4x-3y+5z=7