\(=\left(x^2-4\right)\left(x^2+4\right)-\left(x^4-9\right)\\ =x^4-16-x^4+9=-7\)
=\(\left(x^2-4\right)\left(x^2+4\right)-\left(x^4-9\right)\)
=\(x^4-16-x^4+9=7\)
a. x2(x – 2x3) b. (x2 + 1)(5 – x) c. (x – 2)(x2 + 3x – 4) d. (x – 2)(x – x2 + 4) e. (x2 – 1)(x2 + 2x) f. (2x – 1)(3x + 2)(3 – x) g. (x + 3)(x2 + 3x – 5) h. (xy – 2).(x3 – 2x – i. (5x3 – x2 + 2x – 3).(4x2 – x + 2
Thực hiện phép tính:
a,4.(x+3)/3x2-x : x2+3x/1-3x
b, x+1/x2-2x-8 . 4-x/x2+x
c, 9x+5/2(x-1)(x+3)2- 5x-7/2(x-1)(x+3)2
d, 18/(x-3)(x2-9)-3/x^2-6x+9-x/x^2-9
e, 1/x2-x+1+1/1-x2+2/x3+1
a. x+1/x-2 - x/x+2 + 8/x2 -4
b. x-3/x+1 - x+2/x-1 + 8x/x2 -1
c. x+2/x2-2x + 2/x2+2x + 3x+2/x2-4
d. 4/x - 12/x2+3x + 5/x+3
Bài 5. Tìm x , biết rằng: a) x(x + 5)(x – 5) – (x + 2)(x2 – 2x + 4) = 3
b) (x – 3)3 – (x – 3)(x2 + 3x + 9) + 9(x + 1)2 = 15
c) (x+5)(x2 –5x +25) – (x – 7) = x3
d) (x+2)(x2 – 2x + 4) – x(x2 + 2) = 4
Bài 1: Rút gọn
C) (x2 - 3) (x2 +3) - 5x2 (x + 1)2 - (x2 - 3x) ( x2 - 2x) + 4x (x + 2)2
D) -6x2 (x + 5)2 - ( x - 3)2 + (x2 - 2) (2x2 + 1) - 4x2 ( 3x - 4)2
Tìm x biết:
a/ 5x( x- 3) = x – 3 b/ x3 - x = 0 c/ x2 – 7x + 6 = 0
d/ x2 – 4 + ( x – 2)2 = 0 e/ x2 – 16 –( x +4) = 0 f/ x2 + x – 2 = 0
tìm x:
a)3(2x-3)+2(2-x)=-3
b)2x(x2-2)+x2(1-2x)-x2=-12
c)3x(2x+3)-(2x+5)(3x-2)=8
d)4x(x - 1) - 3(x2-5)-x2=(x-3)-(x+4)
e)2(3x-1)(2x+5)-6(2x-1)(x+2)=-6
Gi ải các phương trình sau (Đặt ẩn phụ)
a)( x2+x)2+4(x2+x)-12=0
b) (x2+2x+3)-9(x2+2x+3)+18=0
c) (x-2)(x+2)(x2-10)=72
Tìm x :
b )(x-1) . ( x2 +x +1) -x.(x-3) . (x+3 )=8
c)( X2 + 2 ) . (x-4 ) - ( X+2 ). ( x2 +4x +4=-16
