Consider the expression [tex]20xy - 4y + 35x - 7.[/tex] Group first two terms and second two terms:
[tex]20xy - 4y + 35x - 7=(20xy - 4y) + (35x - 7).[/tex]
In first brackets the common factor is [tex]4y[/tex] and in second brackets the common factor is [tex]7.[/tex]
Then
[tex](20xy - 4y) + (35x - 7)=4y(5x-1)+7(5x-1)=(5x-1)(4y+7).[/tex]
Answer: correct choice is A.
