A) (X + 1)(X + 3) – X (X + 2) = 7 B) 2X(3X + 5) - X (6X - 1) = 33 C) (3X2 – X + 1)(X – 1) + X2(4 – 3X) = 52D) (12X – 5)(4X – 1) + (3X – 7)(1 – 16X) = 81 2 2E)(X − 3)(X + 3X + + 9) X(5 X ) − = 6X F) (X – 2)3 – X(X + 1)(X – 1) + 6X2 = 5 G) (X – 2)3 – (X +...

Bài 3. Tìm x, biết:

a) (x + 1)(x + 3) – x (x + 2) = 7

b) 2x(3x + 5) - x (6x - 1) = 33

c) (3x

2

– x + 1)(x – 1) + x

2

(4 – 3x) = 5

2

d) (12x – 5)(4x – 1) + (3x – 7)(1 – 16x) = 81

2

2

e)(x − 3)(x + 3x + + 9) x(5 x ) − = 6x

f) (x – 2)

3

– x(x + 1)(x – 1) + 6x

2

= 5

g) (x – 2)

3

– (x + 5)(x

2

- 5x + 25) + 6x

2

= 11

h) (x + 3)

3

– x(3x + 1)

2

+ (2x + 1)(4x

2

– 2x + 1) – 3x

2

= 54