Use a suitable identity to get each of the following products. (i) `(x+3)(x+3)` (ii) `(2y+5)(2y+5)` (iii) `(2a-7)(2a-7)` (iv) `((3a)-1/2)((3a)-1/2)` (v) `(1.1m-0.4)(1.1m+04)` (vi) `(a^2+b^2)(-a^2+b^2)` (viI) `(6x-7)(6x+7)` (vii) `(-a+c)(-a+c)` (viii) `(x/2+(3y)/4)(x/2+((3y)/4)` (ix) `(7a-9b)(7a-9b)`