Question

For each function, y varies directly with x. Find each constant of variation. Then find the value of y when x=0.3.
13. y=2/3 when x=0.2

I know that you set it up as y=kx -> 2/3=k0.2 but I don't know how to solve it where the answer would be one I could work with? Because I have to then take that 'answer' and put it in the problem like so: y=-4x (and let 'answer'=x)

Answer 1

find the value of k first!

2/3 = k* 0.2
correct :)

find k from here.

Answer 2

That's what I'm having trouble on? Like I'd have to either make the decimal into a fraction or vice versa, so that it would either come out as 0.6666...=k0.2 or 10/15=k3/15 and I'm not sure how to find k from either one of those without the problem answer becoming too weird to solve with?

Answer 3

lets keep it in fraction only
if we go for decimals, we need to do approximations

so,
2/3 = k * 2/10
k= 2/3 times 10/2 = 10/3

keep k as 10/3 only

Answer 4

So it'd be y=-(10/3)(3/10) for my final equation to solve?

Answer 5

where did the negative sign come from ?

Answer 6

oops, that was a typo

Answer 7

yeah, without the negative sign, thats correct! just simplify :)

Answer 8

Is my answer 1?

Answer 9

thats correct :)

Answer 10

Thank you so much!

Answer 11

welcome ^_^