`# \text {DNamNgV}`
`(4x - 1)^2 - 9x^2`
`= (4x - 1)^2 - (3x)^2`
`= (4x - 1 - 3x)(4x - 1 + 3x)`
`= (x - 1)(7x - 1)`
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`@` CT: `A^2 - B^2 = (A - B)(A + B)`
(4x-1)^2-9x^2
=(4x-1-3x)(4x-1+3x)
=(x-1)(7x-1)
Rút gọn:
a) A=(4-x)(16+4x+x2)-(4-x)3
b) B=(3x+2)(9x2-6x+4)-(9x2+6x+4)(3x-2)
c) C=(x+1)(x2-x+1)-x(x+1)2
Tìm x
(2x+1)2-4x(x+3)=9
x2-12x=-36
a,x3+3x2+3x+1
b,x2+6x+9
c,-x3+9x2-27x+27
d,x2+4x+4
k,10x-25-x2
f,(x+y)2-9x2
g,8x3+42x2y+16xy2+6xy+y3
Bài 1: Tìm x thỏa mãn:
a) 9x2-1=3(3x-1)
b) (x2-3x+2)2+(-x2+4x-4)3-(x-2)3=0
Tìm x,biết
a)4x 9x2-1=0
b)(x+2)2 -(x+2)(x-3)=0
c)2x3-4x2+2x=0
d)(x-1)2-(2x+1)2=0
a)9x2 – 49 = 0
b)(x – 1)(x + 2) – x – 2 = 0
c)(4x + 1)(x - 2) - (2x -3)(2x + 1) = 7
d)x(3x + 2) + (x + 1)2 – (2x – 5)(2x + 5) = 0
e)(x + 3)(x2 – 3x + 9) –x(x – 1)(x + 1) – 27 = 0
f)(4x-3)^2-3x(3-4x)=0
tìm gtln của 2x2+4x+9x2+2x+4/9x2+2x+4,
Giải các phương trình sau:
a/ (3x – 2)(4x + 5) = 0
b/ (2,3x – 6,9)(0,1x + 2) = 0
c/ (4x + 2)(x2 + 1) = 0
d/(2x + 7)(x – 5)(5x + 1) = 0
e/ (x – 1)(2x + 7)(x2 + 2) = 0
f/ (3x + 2)(x2 – 1) = (9x2 – 4)(x + 1)
Giải các phương trình sau:
a) x - 5(x - 2) = 6x
b) 23 + 3x2 - 32x = 48
c) (3x + 1)(x - 3)2 = (3x + 1)(2x - 5)2
d) 9x2 - 1 = (3x + 1)(4x + 1)
