Suppose x varies directly with y and x = 29 when y=-87. What is the constant of variation and what is the value of x when y=-189?

(hurry! ) which expression is equivalent to the following complex fraction?

An unknown number of kids and buses are getting assigned. when assigning 4 kids to each bus, there are 2 kids that aren't placed in a bus. when assigning 8 kids to each bus, there are 2 empty buses. how many total kids are there?

I’ve been trying all day to figure this puzzle out. i need the work for it aswell. it is a factoring polynomials tarsia. the image is below.