2 + 4 + 6 + 8 + ... + 2.x = 210
=> 2.1 + 2.2 + 2.3 +2.4 + ... + 2.x = 210
=> 2.( 1 + 2 + 3 + 4 + ... +x ) = 210
=> 2. [ x.( x+ 1) /2 ] = 210
=> x. ( x + 1 ) = 210
hay x.( x + 1) = 14.(14 + 1)
Vậy x = 14
1) (x + 1/2).(2/3 - 2x) = 0 2) 2/3x + 1/2x = 5/2 : 3 và 3/4 3) (2x - 3)(6 - 2x)= 0 4) -5(x + 1/5) - 1/2(x - 2/3) = 3/2x - 5/6
1,x=3x2
2,(x+5)(x-3)-(x-30)=0
3,(2x-6)(x+4)+2(2x-6)=0
4,(2x-5)(x+9)+6x-15=0
3,(2x-5)(x+6)+8x-20=0
( 2x + 2 ) + ( 2x + 4 ) + ( 2x + 6 ) + ...+ ( 2x + 100 )
x^2+2x+6=x(x+4)2x+6
rut gon
a,3x(2x-7)-3x(4x-5)
b,(-7x+8)(-2x+3)-7x(2x-4)
c,(2x-3)(3x2-2x+4)-(2x-3)(3x+4)
d,(-2+7)(3x-6)-(4x-5)(2x-6)
|2x+6|+ |x+2| + |2x+2| =4 tìm x
2+4+6+...+2x+(2x+2)=10050
Tính x
tìm số nguyên x
5/x+1+4/x+1=3/-13
-x+2+2x+3+x+1/4+2x+1/6=8/3
3/2x+1+10/4x+2-6/6x+2=12/26
giúp mình mik đang vội]
giải các bất phương trình sau và biểu diễn nghiệm trên trục số:
a)2x+2>4
b)3x+2.-5
c)10-2x>2
d)1-2x<3
e)10x+3-5x<=14x+12
f)(3x-1)<2x+4
g)4x-8>=3(2x-1)-2x+1
h)x^2-x(x+2)>3x-1
i)x+8>3x-1
j)3x-(2x+5)<=(2x-3)
k)(x-3)(x+3)<x(x+2)+3
l)2(3x-1)-2x<2x+1
m)3-2x/5>2-x/3
n)x-2/6-x-1/3<=x/2
o)x+1/3>2x-1/6-2
p)1+2x+1/3>2x-1/6-2
q)x+5/6-2x+1/3<=x+3/2
r)5x+4/6-2x-1/12>=4
