Bài 1 làm tính nhân

2x.(x^2-7x-3)

(-2x^3+y^2-7xy).4xy^2

(-5x^3).(2x^2+3x-5)

(2x^2-xy+y^2).(-3x^3)

(x^2-2x+3).(x-4)

(2x^3-3x-1).(5x+2)

Bài 2 Thực hiện phép tính

A,(2x+3y^2)

B, (5x-y)^2

C, (2x+y^2)^3

D, ( 3x^2-2y)^3

2x.(x^2-7x-3)

(2x^2 + y^2-7xy).4xy^2

(-5x^3).(2x^2 + 3x -5)

(2x^2 – xy+y^2).(-3x^3)

(x^2 – 2x+3).(x-4)

(2x^3-3x-1).(5x+2)

Bài 209. Rút gọn các biểu thức sau:

a) A = (3x + 1)² - 2(3x + 1)(3x + 5) + (5x + 5)²;

b) B = (3 + 1)(3² + 1)(3⁴ + 1)(3⁸ + 1)(3¹⁸ + 1)(3³² + 1);

c) C = (a + b - c)² + (a - b + c)² - 2(b - c)²;

d) D = (a + b + c)² + (a - b - c)² + (b - c - a)²+ (c - b - a)²;              E = (a + b + c + d)² + (a + b - c - d)² + (a + c - b - d)² + (a + d - b - c)²;

g) G = (a + b + c)³ - (b + c - a)³ - (a + c - b)³ + (a + b - c)³;

h) H = (a + b)³ + (b + c)³ + (c + a)³ - 3(a + b)(b + c)(c + a).

Bài 7. Rút gọn các biểu thức sau:

a) A = (3x + 1)² - 2(3x + 1)(3x + 5) + (5x + 5)²;

b) B = (3 + 1)(3² + 1)(3⁴ + 1)(3⁸ + 1)(3¹⁸ + 1)(3³² + 1);

c) C = (a + b - c)² + (a - b + c)² - 2(b - c)²;

d) D = (a + b + c)² + (a - b - c)² + (b - c - a)²+ (c - b - a)²;              E = (a + b + c + d)² + (a + b - c - d)² + (a + c - b - d)² + (a + d - b - c)²;

g) G = (a + b + c)³ - (b + c - a)³ - (a + c - b)³ + (a + b - c)³;

h) H = (a + b)³ + (b + c)³ + (c + a)³ - 3(a + b)(b + c)(c + a).

Tìm x, biết:

a) (2x + 1)² - 4(x + 2)² = 9;                            b) (x + 3)² - (x - 4)( x + 8) = 1;

c) 3(x + 2)² + (2x - 1)² - 7(x + 3)(x - 3) = 36;

d)(x - 3)(x² + 3x + 9) + x(x + 2)(2 - x) = 1;

e) (x + 1)³ - (x - 1)³ - 6(x - 1)² = -19.

Thực hiện phép tính
a) \(\frac{\text{x + 9}}{x^2 - 9}-\frac{\text{3}}{\text{x^2 + 3x}}\)

b) \(\frac{\text{3x + 5 }}{\text{x^2 - 5x }}+\frac{\text{ 25 - x }}{\text{25 - 5x }}\)

c) \(\frac{\text{3 }}{\text{2x }}+\frac{\text{3x - 3 }}{\text{2x - 1 }}+\frac{ 2x^2 + 1 }{\text{4x^2 - 2x }}\)

d) \(\frac{\text{1}}{\text{3x - 2 }}-\frac{1}{\text{3x + 2 }}- \frac{\text{3x - 6}}{\text{4 - 9x^2}}\)
e) \(\frac{\text{18 }}{\text{(x - 3)(x^2 - 9) }}-\frac{\text{3 }}{\text{x^2 - 6x + 9 }}-\frac{\text{x}}{\text{x^2 - 9}}\)
g) \(\frac{\text{x + 2 }}{\text{x + 3 }}-\frac{\text{5 }}{\text{x^2 + x - 6 }}+\frac{\text{1}}{\text{2 - x}}\)
h) \(\frac{\text{4x }}{\text{x + 2 }}-\frac{\text{3x }}{\text{x - 2 }}+\frac{\text{12x}}{\text{x^2 - 4}}\)
i) \(\frac{\text{ x + 1 }}{\text{ x - 1 }}-\frac{\text{ x - 1 }}{\text{ x + 1 }}-\frac{\text{4}}{\text{1 - x^2}}\)
k) \(\frac{\text{ 3x + 21 }}{\text{ x^2 - 9 }}+\frac{\text{2 }}{\text{x + 3 }}-\frac{\text{3}}{\text{x - 3}}\)

Bài 1: Rút gọn biểu thức:

a) x^2 (x +4)(x –  4) – (x^2 +1)(x^16 – 1)      

b) 2x^2 (x – 2) + 3x(x^2 – x – 2) – 5(3 + x^2 )

c) 3(2^2 + 1)(2^4 + 1)(2^8 + 1)(2^16 + 1)

d) (6x +1) ^2 + (6x –1) ^2  – 2(6x +1)(6x –1)

Bài 2: Tính nhanh giá trị của mỗi biểu thức sau:

a) 1,6  + 4.0,8.3,4 + 3,4                           

b) 3^4 .5^4 – (15^2 + 1)(15^2 –1)

c) 34^2 + 66^2 + 68.66                               

d) x  – 12x  + 12x  – 12x +111 tại x = 11

Bài 1: Rút gọn biểu thức:

a) x^2 (x +4)(x –  4) – (x^2 +1)(x^16 – 1)      

b) 2x^2 (x – 2) + 3x(x^2 – x – 2) – 5(3 + x^2 )

c) 3(2^2 + 1)(2^4 + 1)(2^8 + 1)(2^16 + 1)

d) (6x +1) ^2 + (6x –1) ^2  – 2(6x +1)(6x –1)

Bài 2: Tính nhanh giá trị của mỗi biểu thức sau:

a) 1,6  + 4.0,8.3,4 + 3,4                          

b) 3^4 .5^4 – (15^2 + 1)(15^2 –1)

c) 34^2 + 66^2 + 68.66                               

d) x  – 12x  + 12x  – 12x +111 tại x = 11

a, (x-1)³ - x(x-1)² = 5(2-x) - 11(x+2)

b, (x-2)³ + (3x-1)(3x+1) = (x+1)³

c, $\frac{2x-1}{5}-\frac{x-2}{3}=\frac{x+7}{5}$$\frac{\mathrm{<strong>2</strong>}\mathrm{<strong>x</strong>}<strong>-</strong>\mathrm{<strong>1</strong>}}{\mathrm{<strong>5</strong>}}<strong>-</strong>\frac{\mathrm{<strong>x</strong>}<strong>-</strong>\mathrm{<strong>2</strong>}}{\mathrm{<strong>3</strong>}}<strong>=</strong>\frac{\mathrm{<strong>x</strong>}<strong>+</strong>\mathrm{<strong>7</strong>}}{\mathrm{<strong>5</strong>}}$

d, $\frac{2\left(x-3\right)}{7}+\frac{x-5}{3}=\frac{13x+4}{21}$$\frac{\mathrm{<strong>2</strong>}<strong>(</strong>\mathrm{<strong>x</strong>}<strong>-</strong>\mathrm{<strong>3</strong>}<strong>)</strong>}{\mathrm{<strong>7</strong>}}<strong>+</strong>\frac{\mathrm{<strong>x</strong>}<strong>-</strong>\mathrm{<strong>5</strong>}}{\mathrm{<strong>3</strong>}}<strong>=</strong>\frac{\mathrm{<strong>13</strong>}\mathrm{<strong>x</strong>}<strong>+</strong>\mathrm{<strong>4</strong>}}{\mathrm{<strong>21</strong>}}$

e, $\frac{\left(x+10\right)\left(x+4\right)}{12}-\frac{\left(x+4\right)\left(2-x\right)}{4}=\frac{\left(x+10\right)\left(x-2\right)}{3}$