Simplify the following: (i) (1.5x−4y)(1.5x+4y+3) (ii) (x+y)(2x+y)+(x+2y)(x−y) (iii) (a2+5)(b3+3)+5
Find the value of (x+y)(2x+y)+(x+2y)(x−y) when x=−2 and y=−1