f(x) = (2X - 5)² - (4X - 3) (2X+1)
=(2X)² - 2 x (2X x 5 ) + 5² -(4X x 2X +4X +1 -3 x 2X - 3 x 1)
= 4X² - 20X + 25 - (8X+4X-6X-3)
= 4X² - 20X + 25 - 6X + 3
f(X) =4X² - 26X + 28
G(X)= (4X - 2)² - (3X+5)²
=(4X)² - 2(4X x 2) - ((3X)² + 2(3X x 5) +5²
= 16X² -16X +4 - (9X² +30X + 25)
= 16X²-16X + 4 - 9X² - 30X - 25
= 16X² - 9X² - 16X - 30X -25 + 4
= 7X² - 46X - 21
