a, 3(x2 - 2x + 1) - 3x( x - 5) = 1
=> 3x2 - 6x + 3 - 3x2 + 15x = 1
=> 9x + 3 = 1
=> x = \(\dfrac{1-3}{9}\) = \(\dfrac{-2}{9}\)
b, (2x)2 + 4x + 1 - 4( x2 + 4x + 4) = 9
=> 4x2 + 4x + 1 - 4x2 - 16x - 16 = 9
=> -12x - 15 = 9
=> x = \(\dfrac{9+15}{-12}\)= -2
1, ( x+1/3)^3
2, ( 2x+y^2)^3
3, ( 1/2x^2+1/3y)^3
4, ( 3x^2-2y)^3
5, ( 2/3x^2-1/2y)^3
6, ( 2x+1/2)^3
7, ( x-3)^3
8, ( x+1).(X^2+3x+9)
9, ( x-3).( x^2+3x+9)
10, ( x-2).( x^2+2x+4)
11, ( x+4).( x^2-4x+16)
12, ( x-3y).( x^2+3xy+9y^2)
13, ( x^2-1/3). ( x^4+1/3x^2+1/9)
14, ( 1/3x+2y).( 1/9x^2-2/3xy+4y^2)
Đưa về HĐT
Rút gọn :
1. (2x-5)(3x+1)-(x-3)^2+(2x+5)^2-(3x+1)^3
2. (2x-1)(2x+1)-3x-2)(2x+3)-(x-1)^3+(2x+3)^3
3. (x-2)(x^2+2x+4)-(3x-2)^3+(3x-4)^2
4. (7x-1)(8x+2)-(2x-7)^2-(x-4)^3-(3x+1)^3
5. (5x-1)(5x+1)-(x+3)(x^2-3x+9)-(2x+4)^2-(3x-4)^2+(2x-5)^3
6. (4x-1)(x+2)-(2x+5)^2-(3x-7)^2+(2x+3)^3=(3x-1)^3
Bài 3. Rút gọn các đa thức sau
a/ (2x-3)(4x^2+6x+9)- (2x+1)(4x^2 - 2x +1)
b/ (x+ 2)(x^2- 2x+4) – (x^3- 2)
c/ (3x+ 5)(9x^2 - 15x +25)- 3x(3x-1)(3x+1)
d/ x^6 - (x^2 + x +1)(x^2 - 1)(x^2 - x+ 1)
Tìm x: a)(2x+1)(1-2x)+(1-2x)^2=18
b) 2(x+1)^2-(x-3)(x+3)-(x-4)^2=0
c) (x-5)^2-x(x-4)=9
d) (x-5)^2+(x-4)(1-x)=0
A, (x-2)^2=4x^2+4x+1 B, 25x^2-9=0 C, (2x-1)^2+(x+3)^2-5(x+7)(x-7)=0 D, (2x+1)(x-4)-2(x-3)^2=8 E, (3x-1)^2=(5-x)^2
Tìm x. biết:
a/12(x-2)(x+2)-3(2x+3)2 =52
b/(2x+1)2 -4(x-1)(x+1)+2x=5
c/(x-2)3-(x-3)(x2+3x+9)+6(x+1)2=15
d/(x+2)(x2-2x+4)-x(x2+2)=15
e/ 12(x-2)(x+2)-3(2x+3)2=57
f/ (3-x)(3+x)+(3x-1)2+6x=522
g/(2x+1)2-4(x-1)(x+1)+2x=5
Bài 1: Thực hiện phép tính
1, (3y +1/3y^4)^2
2, (-3x^2 -1/2x)^2
3, (x^2 +2x -3)^2
4, 3 (x+3) (x-3) - (x-9)^2
5, (x^n +x^n:1)^2
6, (5x-3y)^2 - (5x +3y)^2
7, (3x -x^2 +5)^2
8, (-2x +5y)^3
9, (1/3x^2 -5y^3)^3
10,(m^2n^3+n^2m^3) (m^2n^3 - n^2m^3)
11, (7x+6y)^2 - (7x +6y) (7x -6y)
12, (x-y)^2 +(y+x)^2 - (2x -y)^z
13, (a-b)^3 + (a+b)^3
14, (a-b)^3 -(a-b)^3
15, (3x-5y)^4 - (3x +5y)^4
Mọi người làm giúp mình vs
Tìm x biết
a,(x+4)^2-(x+1)(x-1)=16
b,(2x-1)^2-(x+3)-5(x-7)(x+7)=0
c,3(x-1)^2-3x(x-5)=1
d,6(x-2)^2+(5x-2)^2-4(3x-1)(5x-2)=0
e,(x-2)^3-x^2(x-6)=4
g,(x-1)(x^2+x+1)-x(x+2)(x-2)=5
h,(x-1)^3-(x+3)(x^2-3x+9)+3(x^2-4)=2
a)(x-3y)(x^2+3xy+9y^2)
b)(x^2-3)(x^4+3x^2+9)
c)(x+2y+z)(x+2-z)
d)(2x-1)*(4x^2 +2x+1)
e) (5+3x)^3
1, tìm x :
a) (x+2).(x+3)-(x-2).(x+5)=0
b) (2x+3).(x-4)+(x-5).(x-2)=(x-4).(3x-5)
c) (3x-5).(7-5x)-(5x+2).(2-3x)=3
d)(x-7).(x+7)-(x-4)2-x=10+3
e) (x+1/2)2-(x-1).(x+1)=2x-1
2, Thu gọn :
a) (x+5)2-(3-x)2-2(x-4).(x+4)
b)4(x-1)2+(2x+3)2-8(x-2)(x+2)