Giải
1) 3xy2 : 5x = \(\frac{3}{5}\)y2
2) 15x4yz3 : 4xyz = \(\frac{15}{4}\)x3z2
3) (4x2y2 - 12xy3 - 7x) : 3x = \(\frac{4}{3}\)xy2 - 4y3 - \(\frac{7}{3}\)
4) (14x4y2 - 12xy3 - x) : 4x = \(\frac{7}{2}\)x3y2 - 3y3 - \(\frac{1}{4}\)
5) (6x2 + 13x - 5) : (2x + 5) = (3x - 1)(2x + 5) : (2x + 5) = 3x - 1
6) (2x4 + x3 - 5x2 - 3x - 3) : (x2 - 3)
= 2x4 + x2 - 6x2 + x3 - 3 - 3x : x2 - 3
= x2(2x2 + x + 1) - 3(2x2 + x + 1) : x2 - 3
= (2x2 + x + 1)(x2 - 3) : x2 - 3
= 2x2 + x + 1
Bài 1:Thực hiện các phép tính
a. (x5 +4x3 - 6x2):4x2
b. (x3 +x2-12) : (x-2)
c. (-2x5+3x2-4x3):2x2
d. (x3 - 64):(x2 + 4x + 16)
Bài 2:Rút gọn biểu thức
a. 3x (x - 2)- 5x (1 - x) - 8(x2 - 3)
b.(x - y) (x2 + xy + y2)+2y3
c. (x - y)2 + (x+y)2 - 2(x-y) (x+y)
Tìm x
a)(2x+1)2-4(x+2)2 =9
b)(3x-1)2 +2(x+3)2 +11(x+1)(1-x)=6
c)(x+1)3 - x2 (x+3)=2
d)(x-2)3 -x(x+1)(x-1)+6x2 =5
e)(x-3)(x2 +3x +9)-x(x+4)(x-4)=5
g)(x-2)3 -(x+5)(x2 -5x+25)+6x2 =11
Bài 4: Giải các phương trình sau
a) 4(x+5)(x+6)(x+10)(x+12)=\(3x^2\)
b) \(\frac{1}{x^2-3x+3}+\frac{2}{x^2-3x+4}=\frac{6}{x^2-3x+5}\)
c) \(\frac{4x}{4x^2-8x+7}+\frac{3x}{4x^2-10x+7}=1\)
d) \(\dfrac{2x}{2x^2-5x+3}+\dfrac{13x}{2x^2+x+3}=6\)
d) (5x+3) ( 4x-1) +(10x-7) (-2x+3) =27
e)(8x-5) (3x+2) -(12x+7) (2x-1)=17
f) (5x+9) (6x-1) -(2x-3)( 15z+1) = -190
g) 6x(5x+3) + 3x(1-10x) =7
h) (3x-3) (5 -21x) +(7x+4)(9x-5) =44\
i) (x+1)(x+2)(x-5)-x2 (x+8)=27
Tìm x, biết:
(4x-1)2-(3x+2)(3x-2)= (7x-1)(x+2)+(2x+1)2-(4x2+7)
(5x-1)(x+1)-2(x-3)2= (x+2)(3x-1)-(x+4)2+(x2-x)
(-x+5)(x-2)+(x-7)(x+7)= (3x+1)2-(3x-2)(3x+2)
(2x+3)2-(5x-4)(5x+4)= (x+5)2-(3x-1)(7x+2)-(x2-1)
(1-3x)2-(x-2)(9x+1)= (3x-4)(3x+4)-9(x+3)2
thực hiện phép tính
a.\(\dfrac{x}{3x+y}+\dfrac{x}{3x-y}-\dfrac{2xy}{y^2-9x^2}\)
b.\(\dfrac{4x+5}{x^2+5x}-\dfrac{3}{x+5}\)
Phân tích các đa thức sau thành nhân tử :
a, x^2 + 4x + 3
b,16x - 5x^2 - 3
c, 2x^2 + 7x + 5
d, 2x^2 + 3x - 5
e,x^3 - 3x^2 + 1 - 3x
f, x^2 - 4x - 5
g, ( a^2 + 1 )^2 - 4a^2
h, x^3 - 3x^2 - 4x + 12
i, x^4 + x^3 + x + 1
k, x^4 - x^3 - x^2 + 1
l, ( 2x + 1 )^2 - ( x - 1 )^2
m,x^4 + 4x^2 - 5
Tìm x
1) 2-3x=5x +10
2) 13-7x =4x-20
3) 11-9x =3 -7x
4) 5( 2x -3 ) - 4 ( 5x-7) = 19-2 ( x+11)
5) 4 ( x+3) -7x+17= 8( 5x -1)+166
6) 17-14(x+1)=13-4(x+1)-5(x-3)
7)5x-3,5+ ( 3x-4)
8) 7 (4x +3)- 4 (x-1)= 15 (x+0,75)+7
9) 3x -2,42 + 0,8= 3,38 - 0,2x
10) 9 ( x+3) + 6 = 4 ( 5x +9 )
1. 6x(x - 10) - 2x+20=0 6. 3x2 - 6x+3=0
2. 3x2(x - 3) + 3(3 - x)=0 7. 4x2 - 10x+2=0
3. x2 - 8x+16=2(x -4) 8. x2 - 12x -18=0
4. x2 - 16 + 7x ( x+4)=0 9. 3x2 - 10x+3=0
5. x2 - 13x - 14=0 10. 5x2 - 10x+10=0
