Her vertical position is described by y(t). She reach the ground when y(t) = 0 so:

She reach the ground after 2.5 seconds and she will be:

(meters) from the cliff.
question number 36 the answer is always true because rational numbers are numbers that can be turned into fractions or simple fractions easily and any integers that is positive added together will provide a positive answer.
37. the answer is always true because and a negative integer and a negative integer added together will give a negative answer.
38. sometimes true. a positive intergee plus a negative interger can give a positive or negative answer. eg -3+2=-1 but -4+8=4
39. always true. + multiply + =+
40. never true. - multiply - = +
Isolate the variable y
Line a: 3y = x+6
y = 1/3x + 2
Line b: 3y = x+18
y = 1/3 x + 6
Line c: 3y = 2x+9
y = 2/3x +3
Explanation:
Lines a and b are parallel because they have the same slope of 1/3.
I would agree with the answer of c, hope this helps
Company b is of course offering the lower price because it cost less and it weigh the same.