Question

Question 5 Unsaved Factor the 4 term polynomial using grouping: 20xy - 4y + 35x - 7 Question 5 options:
(4y + 7)(5x - 1)
(4y - 7)(5x + 1)
(4y + 1)(5x - 7)
(4y - 1)(5x + 7)

Answer 1

Consider the expression $20xy - 4y + 35x - 7.$ Group first two terms and second two terms:

$20xy - 4y + 35x - 7=(20xy - 4y) + (35x - 7).$

In first brackets the common factor is $4y$ and in second brackets the common factor is $7.$

Then

$(20xy - 4y) + (35x - 7)=4y(5x-1)+7(5x-1)=(5x-1)(4y+7).$

Answer: correct choice is A.