(4х-1)(4х+1)-(4х+3)²=16х²-1-(16х²+24х+9)=16х²-1-16х²-24х-9=-10-24х.
★ (a-b)(a+b)=a²-b² ★
★ (a+b)²=a²+2ab+b² ★
(4х-1)(4х+1)-(4х+3)²=16х²-1-(16х²+24х+9)=16х²-1-16х²-24х-9=-10-24х.
★ (a-b)(a+b)=a²-b² ★
★ (a+b)²=a²+2ab+b² ★