Tính: a/ (x + 3y)^2, b/ (5x + 2)^2, c/ (x + 1/4)^2, d/ (1/3x + 1/2y)^2, e/ (3x + 1)(3x - 1), f/ (x^2 + 1)(x^2 - 1)

1/ tính
a/ (x+3y)^2
b/(5x+2)^2
c/(x+1/4)^2
d/(1/3x+1/2y)^2
e/(3x+1)(3x-1)
f/(x^2+1)(x^2-1)
g/(x^2+2/5y)(x^2-2/5y)
h/(x+1)^2-(x-2)^2-3(x+1)(x-1)
i/(x+2)(x-2)-(x+6)^2