If y varies directly as x and y =5 when x=2, how do you find y when x=6?

1 Answer
May 12, 2018

Answer:

The relationship between x and y is #y=5/2x#, therefore #y=15# when #x=6#

Explanation:

The way I read your question is that we can write the relation between x and y on the form #y=ax#.

In this case we know that #5=a*2# or #a=5/2#, so that the relationship between y and x can be written on the form
#y=5/2x#.

In that case we can just plug in x=6 in the equation, in which case we get
#y=5/2*6=15#

An easy way of finding the same result is with a graph:
graph{y=5/2x [-9.67, 30.87, -1.92, 18.34]}

Reading off our graph we can see that the line goes through (2, 5) and (6, 1).