could someone help me understand this?

Question

Factor the following trinomial.

 

35x^2+46x+15

Answer 1

35x² + 46x + 15

 

(7x + 5)(5x + 3)

 

 

Useful tips for knowing the signs of each binomial factor:

 

(a) If the trinomial contains two + signs, both factors will contain + signs.

(b) If the trinomial's first sign is - and the second is +, both factors will have - signs.