^ : mũ 2 a. ( 3x +2 ) ^ b. (y- 1/4 ) ^ c. ( x- 1/2 )^ d. (3 a^b + 1/3 ab^ )^

`a) (3x+2)^2 = (3x)^2 + 2.3x.2 + 2^2 = 9x^2 + 12x + 4`

`b) (y-1/4)^2 = y^2 – 2. y . 1/4 + (1/4)^2 = y^2 – 1/2y + 1/16`

`c) (x-1/2)^2 = x^2 – 2. x . 1/2 + (1/2)^2 = x^2 – x + 1/4`

`d) (3a^2b + 1/3ab^2)^2`

` = (3a^2b)^2 + 2 . 3a^2b . 1/3ab^2 + (1/3ab^2)^2`

` = 9a^4b^2 + 2a^3b^3 + 1/9a^2b^4`