BT3/6. Tìm x, biết

a/ 2x(12x-5)-8x(3x-1)=30

b/3x(3-2x)+6x(x-1)=15

Cho a3 + b3 + c3 = 0

CMR a3b3 + 2b3c3 + 3a3c3 \(\le\)0

Cho 2aa + bb = 3cc

Tính: 2015a-b + 2016b-c + 2017c-a

a) (x+2).(x-5) > 0

b) (x-3).(x+4) < 0

a,5(x-2)+3x (x-2)=0

b,2/3+5/2:x=2/4

c,2x(x-1/7)=0

d,11/12-(2/5+x)=2/3

e,3/4+1/4:x=2/5

g,2/3x+5/7=3/10

Tìm x:

a) \(\dfrac{2}{3}\) - \(\dfrac{1}{3}\) . ( x - \(\dfrac{3}{2}\) ) - \(\dfrac{1}{2}\) . ( 2x + 1 ) = 5

b) ( x + \(\dfrac{1}{2}\) ) . ( \(\dfrac{3}{4}\) - x ) = 0

c) \(\dfrac{2x-1}{-3+2}\) = 0

Tìm x, biết

a) x(2x-7)-4x+14=0

b) (2x+5)(3x-1)-(2x+5)=0

c) \(\left(2x-3\right)^2-6x+9=0\)

A=\(\left(\dfrac{1-x^3}{1-x}-x\right):\dfrac{1-x^2}{1-x-x^2+x^3}\)

tìm a, b,c biết:

\(ax^3+bx^2+c\) chia hết cho x -2 và chia cho x2 - 1 dư 2x+5

Tính giá trị biểu thức

A) 5n+1 - 4 . 5n

B)62 . 64 - 43 ( 36 -1)