tim x biet : x x 6 = 8850
x x 6 =8850
x.6=8850
x=8850:6
x=1475
k nhe
Tìm x : b) 25 x X = 8850
a, tim x€Z biet (x-6) chia het cho (x-5)
b, tim x€Z, y€Z biet (x-1).(xy-5)=5
tim x biet 2/(x+2)+(x+4)+4/(x+4)+(x+6)+6/(x+6)+(x+14)=x/(x+2)+(x+14)
Tim X biet: X x 7+6=Xx8
vì Xx7+6=Xx8
=>Xx7+6=Xx7+x
=>X=6
tim x biet x+6=9
tim x biet 6 : (x-1)
tim x,biet
x(x-2)-3(x+1)=x(x-6)
x(x-2)-3(x+1)=x(x-6)
=>x2-2x-3x-3=x2-6x
=>x2-2x-3x-3-x2+6x=0
=>(x2-x2)+(-2x-3x+6x)-3=0
=>0+x-3=0
=>x=3
x(x-2)-3(x+1)=x(x-6)
=>x2-2x-3x-1=x2-6x
=>x2-2x-3x-1-x2+6x=0
=>(x2-x2)+(-2x-3x+6x)-1=0
=>0+x-1=0
=>x=1
x(x-2)-3(x+1)=x(x-6)
=>x2-2x-3x-3=x2-6x
=>x2-2x-3x-3-x2+6x=0
=>(x2-x2)+(-2x-3x+6x)-3=0
=>0+x-3=0
=>x=3
Tim x biet (x + 2) + (x + 4) + (x + 6) + ... + (x + 100) = 2700
(x+2)+(x+4)+(x+6)+...+(x+100) = 2700
=> 50x + (2+4+6+...+100) = 2700
=> 50x + 2550 = 2700
=> 50x = 2700 - 2550
=> 50x = 150
=> x = 3
(x+2)+(x+4)+(x+6)+...+(x+100)=2700
>50x+(2+4+6+...+100) =2700
>50x+2550 =2700
>50x =2700-2550
> 50x =150
> x =150:50
>x =3
Vậy X=3 thì (x+2)+(x+4)+(x+6)+...+(x+100) =2700