Question

let y =21 and x =1.5. If y varies directly with x, fins y when x =9

Answer 1

y varies directly with x
how do you write this as an equation?

Answer 2

hint: On your previous post it said how to

Answer 3

I don't understand it..

Answer 4

can you give me a written example

Answer 5

Well on your previous post is said
that y varies directly as x meant y=kx
where k is a constant

Answer 6

So we have the equation y=kx

Answer 7

Now you are also given an order pair on this line x=1.5,y=21
enter these values in the equation and solve for k

Answer 8

Direct variation is \(\dfrac{x}{y}=C\) for some constant \(C\). The first two value give you enough information to find \(C\), and then use your new formula to solve the problem.

Answer 9

What did you get for k?