Verified answer

5.

x²-2x(x-3)+(x-3)²=9

x²-2x²+6x+x²-6x+9=9

9=9 - верно

Ответ:

а) (4а²+b²)(2a - b)(2a + b) = (4a²+b²)(4a²-b²) = 16a⁴- b4

б) (b²c³ - 2a²)(b²c³ + 2a²) = b⁴c`6 - 4a⁴

в) (а⁴ - 1) - (9+а²)² = (а⁴ - 1) - (81 + а⁴ + 18а²) = а⁴ - 1 - 81 - а⁴ - 18а² = - 82 - 18а²

2) х² - 2х(х - 3) + (х - 3)³ = 9

х² - 2х(х - 3) + (х³ + 27 - 6х) = 9

х² - 2х² + 6х + х³ + 27 - 6х = 9

-1х² + х³ + 27 = 9