Answer :
[tex](2a-1)(8a-5)=2a\cdot 8a-2a\cdot 5-8a\cdot 1-5\cdot (-1)=\\ \\=16a^2-10a-8a+5=16a^2-18a +5[/tex]
(2a - 1) (8a - 5)
= {2a(8a - 5)} - {1(8a - 5)}
= 16a² - 10a - 8a + 5
= 16a² - 18a + 5
= {2a(8a - 5)} - {1(8a - 5)}
= 16a² - 10a - 8a + 5
= 16a² - 18a + 5