Question

1, Triển khai các hàng đẳng thức sau

a) (x-1)^2

b) (x+2)^2

c) (y+2a)^2

d) (44a^2-96^2)

e) (2x-y)^3

g) (3a+6)^3

h) 8a^3-27y^3

y) (64a^3-b^3)

Answer 1

a) (x - 1)² = x² - 2x + 1

b) ( x + 2 )² = x² + 4x + 4

c) (y + 2a )² = y² + 4ya + 4a²

Answer 2

e) (2x - y)³ = ( 2x )³ - 3.(2x)².y + 3.2x.y² - y³ = 8x³ - 12x²y + 6xy² - y³

g) (3a+6)³ = (3a)³ + 3.(3a)².6 + 3.3a.6² + 6³ = 27a³ + 162a² + 324a + 216