We use identities (x+a)(x+b) = x²+(a+b)x+ab and x²-y²=(x+y)(x-y)
(i)(x+4)(x+10) = x²+(4+10)x+(4)(10) = x²+14x+40
(ii)(x+8)(x-12) = x²+(8-12)x+(8)(-12) = x²-4x-96
(iii)(3x+4)(3x-5) = (3x)²+(4-5)3x+(4)(-5) = 9x²-3x-20
(iv)(y²+32)(y²-32) = (y²)²-(32)² = y⁴-1024
(v)(3-6x)(3+2x) = (3)²-(6x)² = 9-36x²