tim p
x-3/x^2 + x + 1 = P/x^3 -1
Tim x biet : 20 . 2^x + 1 = 10.4^2 + 1
Tim x : ( 4-x:2)^3 - 1 = 2 . (2^3 - 5 : 2^0 )
20 . 2^x + 1 = 10.4^2 + 1
20 . 2^x + 1 = 10 . 16 + 1
20 . 2^x + 1 = 161
20 . 2^x = 161 - 1
20 . 2^x = 160
2^x = 8
2^x = 2^3
=> x = 3
( 4 - x : 2 )^3 - 1 = 2 . ( 2^3 - 5 : 2^0 )
( 4 - x : 2 )^3 - 1 = 2 . ( 8 - 5 : 1 )
( 4 - x : 2 )^3 - 1 = 2 . 3
( 4 - x : 2 )^3 - 1 = 6
( 4 - x : 2 )^3 = 7
=> ko tìm đc x
1)tim x biet rang:
a)3^x-1=1/243
b)2^x+2^x+3=144
c)81^-2x.27x=9^5
2)tim tiep so ghang thu 5 cua day so sau:-1/a^2;2/a^3;-6/a^4;24/a^5;...
3)tim so tu nhien x biet :
a)4^x+4^x+3=4160
b)2^x-1+5.2^x-2=7/32
tim x biet 1/2(x-2/3)-1/3(2x-3)=x+1/2
choP=(1/(x-2)-x^2/(8-x^3)*(x^2+2x+4)/(x+2)0/1/(x^2-4) tim DKXD va rut gon b tim Min p c tim x nguyen de p chia het cho x^2+1
1 )Tim x, y thuoc Z
x + y = x.y
2) Tim x thuoc Z
(x + 1)+(x+3)+(x+5)+...+(x+99)=0(x-3)+(x-2)+(x-1)+...+10+11=11-12(x-5)+7(3-x)=530(x+2)-6(x-5)-24x=100x + y = x.y
=> xy - x - y = 0
=> (xy - x) - y + 1 = 1
=> x(y - 1) - (y - 1) = 1
=> (x - 1)(y - 1) = 1
=> x - 1 = y - 1 = 1 hoặc x - 1 = y - 1 = -1
=> x = y = 2 hoặc x = y = 0
tim x(x+2)3-3(x+2)2=2(x-1)(x+2)-((1-x)3
tim x : 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)-1/1/2010
tim x ; 1/x(x+1)+1/(x+1)(x+2)+1/(x+2)(x+3)-1/x=1/2010
tim x:
6(x+1)^2-2(x+1)^3-2(x-1)(x^2+x+1)=1
\(6\left(x+1\right)^2-2\left(x+1\right)^3-2\left(x-1\right)\left(x^2+x+1\right)=1\)
\(\Leftrightarrow6\left(x^2+2x+1\right)-2\left(x^3+3x^2+3x+1\right)-2\left(x^3+x^2+x-x^2-x-1\right)=1\)
\(\Leftrightarrow6x^2+12x+6-2x^3-6x^2-6x-2-2x^3-2x^2-2x+2x^2+2x+2=1\)
\(\Leftrightarrow-4x^3+6x+5=0\)
\(\Leftrightarrow x=1.5233401602\)
Tim x biet 1+1/2(1+2)+1/3(1+2+3)+...+1/x(1+2+3+...+x)=115