Develloper & factoriser: (2x-5)²-(x+1)²
(2x-5)²-(x+1)²
= 2x²-2*2x *5 +5² - (x² +2*1*x +1²)
=4x² -20x + 25 - (x² +2x +1)
=4x² -20x + 25 - x²- 2x - 1
= 3x² - 22x +24
