Question

1. (2a-1)^2(2a+1)^2 2.(3a-2b)^2-(3a+2b)^2 3.(x-2y+4)(x+2y-4) 4.2(x+1)^2-1/2(x+2)(x-2)

Answer 1

(2a-1)^2(2a+1)^2
=[(2a-1)(2a+1)]^2
=(4a^2-1)^2
=16a^4-8a^2+1

(3a-2b)^2-(3a+2b)^2
=[(3a-2b)-(3a+2b)][(3a-2b)+(3a+2b)]
=(3a-2b-3a-2b)(3a-2b+3a+2b)
=-4b*6a
=-24ab

(x-2y+4)(x+2y-4)
=[x-(2y-4)][x+(2y-4) ]
=x^2-(2y-4)^2
=x^2-4y^2+16y-16

2(x+1)^2-1/2(x+2)(x-2)
=2x^2+4x+2-1/2(x^2-4)
=2x^2+4x+2-x^2/2+2
=3x^2/2+4x+4