If y varies directly with x, how do you find y when x = 5 if y = -6 when x = 2?

1 Answer
Alan P.
Dec 15, 2015

y=-15

Explanation:

If y varies directly with x then
color(white)("XXX")y/x=c for some constant c

If y=-6 when x=2 then
color(white)("XXX")(-6)/2=c rarr c=-3

That is y/x=-3

So when x=5
color(white)("XXX")y/5=-3

color(white)("XXX") rarr y=-3xx5

color(white)("XXX") rarr y=-15

Related questions
See all questions in Direct Variation
Impact of this question
5351 views around the world
You can reuse this answer
Creative Commons License