If r, s, and t are collinear and rs + st = rt, which of the following is true?

The product of two negative rational numbers is always zero sometimes zero never zero

Pick the expression that matches this description: a polynomial of the 5th degree with a leading coefficient of 7 and a constant term of 6 (choice a) 7x^5+2x^2+6 (choice b) 7x^6−6x^4+5 (choice c) 6x^7−x^5+5 (choice d) 6x^5+x^4+7

Any is very appreciated! (picture is provided below)not sure how to do this at all won't lie