a: =16x^2-(5y-1)^2
=(4x-5y+1)(4x+5y-1)
b: =27x^2-9x-14x-4
=27x^2-23x-4
=27x^2-27x+4x-4
=(x-1)(27x+4)
a) 16x² - 25y² + 10y - 1
= 16x² - (25y² - 10y + 1)
= (4x)² - (5y - 1)²
= (4x - 5y + 1)(4x + 5y - 1)
b) 9x(3x - 1) - 14x - 4
= 27x² - 9x - 14x - 4
= 27x² - 23x - 4
= 27x² - 27x + 4x - 4
= (27x² - 27x) + (4x - 4)
= 27x(x - 1) + 4(x - 1)
= (x - 1)(27x + 4)