a,gt <=> (x-1)^3-x(x^2-4)=5
<=>x^3-3x^2+3x-1-x^3+4x-5=0
<=>-3x^2+7x-6=0
<=>x^2-7/3x+2=0
<=>x^2-7/3x+49/36+23/36=0
<=>(x-7/6)^2=-23/36(vl)
=>không tìm được x
b,gt <=> (x-1)^3-(x+3)^3+3(x^2-4)=2
<=>x^3-3x^2+3x-1-x^3-9x^2-27x-27+3x^2-12-2=0
<=>-9x^2-24x-42=0
<=>9x^2+24x+16=-26
<=>(3x+4)^2=-26(vl)
=> điều tương tự câu a
Rút gọn các biểu thưc sau:
c.(x -1)3 – (x - 1)(x2 +x+1)
d.(x -3)3 – (x - 3)(x2 +3x+9) + 6(x+1)2
Mình cần gấp!!!!!
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
Câu III (2,0 điểm) Tìm x, biết:
a) x(x – 1) – x2 + 2x = 5
b) 2x2 – 2x = (x – 1)2
c) (x + 3)(x2 – 3x + 9) – x(x – 2)2 = 19
Tìm x:
a)2x3-18x=0
b)(3x-2).(2x+1)-6x.(x+2)=11
c)(x-1)3-(x+2).(x2-2x+4)=3.(1-x2)
Tìm x:
a)x.(x-1)-(x-2)2=2
b)x2-9=(x-3).(6-x)
c)x2-x-6=0
Tìm x:
a)x.(x-1)-(x-2)2=2
b)x2-9=(x-3).(6-x)
c)x2-x-6=0
Bài 1: Tìm x:
1) (x-3)3 -( x-3)(x2+ 3x+9) +6( x+1)2+ 3x2 = -33
2) (X-3)( X2+ 3X+9) - X(X-2)( 2+X) = 1
3) (X+2)(X2 - 2X+4) – X(X-3)(X+3) = 26
tìm x , biết
a. 4x(x-5)-(x-1)(4x-3)=5
b. (3x-4)(x-2) = 3x(x-9)-3
c.2(x+3)-x2 -3x=0
d. 8x3-50x=0
e. (4x-30)2-3x(3-4x)
Bài 2: (2 điểm) Tìm x, biết:
a) (3x + 4)2 – (3x – 1)(3x + 1) = 49
b) x2 – 4x + 4 = 9(x – 2)
c) x2 – 25 = 3x - 15
d) (x – 1)3 + 3(x + 1)2 = (x2 – 2x + 4)(x + 2)
