Đáp án:
Giải thích các bước giải:
`a. (2x -1/2)^2`
`=(2x)^2 - 2.2x. 1/2 + (1/2)^2`
`=4x^2 -2x +1/4`
`b. (1/3x-1/4)^2`
`=(1/3 x)^2 - 2.1/3 x .1/4 + (1/4)^2`
`= 1/9 x^2 - 1/6 x + 1/16`
`c. (x-3/2)^2`
`=x^2 - 2.x.3/2 + (3/2)^2`
`=x^2 -3x + 9/4`
`d. (2/3xy+1/2y)^2`
`=(2/3 xy)^2 + 2.2/3 xy .1/2 y + (1/2 y)^2`
`=4/9 x^2 y^2 + 2/3 xy^2 + 1/4 y^2`