Assume that y varies inversely with x. If y = -3 when x = 2.4, what is y when x = 2?

Question

nirmalnema · Answer

x1y1=x2y2
2.4*(-3)=2*y
y=-7.2/2=-3.6

anonymous · Answer

Okay, how do you solve a problem like that? Like, whats the formula?

anonymous · Answer

yx  =  k        ->        (-3)(2.4)  =  k

y(2) = (-3)(2.4)      ->     y  =  (-3)(2.4)/2

nirmalnema · Answer

x1=1/y1
x2=1/y2
so x1y1=1
x2y2=1
therefore x1y1=x2y2

nirmalnema · Answer

@Cubi-Cal  have u got it

anonymous · Answer

Yeah I think so... let me double check.

nirmalnema · Answer

ok.....

anonymous · Answer

The formula for what I wrote is as follows:

You have an inverse proportion, therefore:

y times x will equal a constant.

You are given an initial "y" and "x", so you can derive the constant "k".

anonymous · Answer

Now, "y" times some "x" will give you a known "k" (constant), determined from the first step.  You have "x" and "k", so you can determine the new "y".

anonymous · Answer

All good now, @Cubi-Cal ?

anonymous · Answer

Yessir! (Ma'am) Thanks you two!:)

anonymous · Answer

uw! @Cubi-Cal

anonymous · Answer

Wait, would x=-7.2 or -3.6?

nirmalnema · Answer

x = -3.6