Question

Bài 2. Tính:

a. (x – 2y)²                  

b. (2x² +3)²                 

c. (x – 2)(x² + 2x + 4)             

d. (2x – 1)³

Answer 1

\(\text{a. (x – 2y)^2=x^2- 2x2y+ (2y)^2 =x^2-4xy+4y^2 }\)

\(\text{b. (2x^2 +3)^2= (2x^2)^2+2.2x.3+3^2=16x^4+12x+9}\)

 

Answer 2

\(\text{c. (x – 2)(x^2 + 2x + 4)=x^3-2^3=x^3-6 }\)

Answer 3

\(\text{d. (2x – 1)^3= 2x^3-3.(2x)^2.1+3.2x.1^2-1^3=8x^3-12x^2+6x-1}\)