c: =>x^3+9x^2+27x+27-x^2+6x-9-x^2+6x-9=6x+18
=>x^3+7x^2+39x+9-6x-18=0
=>x^3+7x^2+33x-9=0
=>\(x\simeq0.26\)
d: =>x^3-3x^2+3x-1-x^3-2x^2-x=10x-5x^2-11x-22
=>x^3-5x^2+2x-1=-5x^2-x-22
=>x^3+3x+21=0
=>\(x\simeq2.40\)
a, (3x+2)2 - (3x-2)2 =5x+38 b, 3(x-2)2 +9(x-1) =3(x2+x-3)
c, (x+3)3 -(x-3)2 -(x-3)2 =6x+18 d, (x-1)3-x(x+1)2=5x(2-x)-11(x+2)
e, (x+1)(x2-x+1)-2x=x(x-1)(x+1) f, (x-2)3+(3x-1)(3x+1)=(x+1)3
Bài 4: Tìm x, biết:
a) 3(2x – 3) + 2(2 – x) = –3 ; b) x(5 – 2x) + 2x(x – 1) = 13 ;
c) 5x(x – 1) – (x + 2)(5x – 7) = 6 ; d) 3x(2x + 3) – (2x + 5)(3x – 2) = 8 ;
e) 2(5x – 8) – 3(4x – 5) = 4(3x – 4) + 11; f) 2x(6x – 2x 2 ) + 3x 2 (x – 4) = 8.
Bài 3: Giải các phương trình sau
a. (3x + 2)2 – (3x – 2)2 = 5x + 38
b. 3(x – 2)2 + 9(x – 1) = 3(x2 + x – 3)
c. (x + 3)2 – (x - 3)2 = 6x + 8
d. (x – 1)3 – x(x + 1)2 = 5x (2 – x) – 11(x + 2)
e. (x + 1)(x2 – x + 1) – 2x = x(x – 1)(x + 1)
phân tích đa thức
a)x^4+6x^3+11x^2+6x+1
b)x^4+x^3+x^2+x+1
c)6x^4+5x^3-38x^2+5x+6
d)x^4+5x^3-12x^2+5x+1
Giải các phương trình sau
\(a.\left(3x+2\right)^2-\left(3x-2\right)^2=5x+8\)
\(b.3\left(x-2\right)^2+9\left(x-1\right)=3\left(x^2+x-3\right)\)
\(c.\left(x+3\right)^2-\left(x-3\right)^2=6x+18\)
\(d.\left(x-1\right)^3-x\left(x+1\right)^2=5x\left(2-x\right)-11\left(x+2\right)\)
Rút gọn biểu thức:
a) (6x + 1)^2 + (6x-1)^2 - 2(1+6x)(6x-1)
b) 3(2^2 +1) (2^4 +1) (2^8 +1)(2^16 +1)
c) x(2x^2 - 3) -x^2 (5x +1) +x^2
d) 3x(x-2) - 5x(1-x) - 8(x^2 - 3)
Rút gọn phân thức
a) (6x+1)^2 + (6x-1)^2 - 2(1+6x).(6x-1)
b) x(2x^2 - 3) - x^2(5x+1) + x^2
c) 3(2^2+1).(2^4+1).(2^8+1).(2^16+1)
d) 3x(x - 2) - 5x(1 - x) - 8(x^2 - 3)
rút gọn biểu thức
a.(6x+1)^2-(6x-1)-2(1+6x)(6x-1)
b . x(2x^2-3) -x^2(5x+1)+x^2
c.3(2^2+1)(2^4+1)(2^8+1)(2^16+1)
d.3x(x-2)-5x(1-x-8)(x^2-3)
tìm x biết
a) (6x-3) (2x+4) + (4x-1) (5-3x) = -21
b) 6x (3x+5) - 2x (9x-2) + (17-x) (x-1) + x (x-18) =0
c) (15-2x) (4x+1) - (13-4x) (2x-3) - (x-1) (x+2) + x2=52
d) (8x-3) (3x+2) - (4x+7) (x+4) = (2x+1) (5x-1) - 33
