If z varies jointly with x and y and inversely with w, and z = 7 when x = 2, y= -1, and w = 4, find z when x =3, y = 4, and w =6

Question

nikato · Answer

WELCOME TO OPENSTUDY!

so z varies jointly with x and y and inversely with w is
$$z=\frac{ kxy }{ w }$$

nikato · Answer

and you're given z=7,x=2,and w=4,y=-1
now plug these values in and can you find k?

$$7=\frac{ k(2)(-1) }{ 4 }$$

anonymous · Answer

Is it -14?

johnweldon1993 · Answer

Indeed ^    k = -14

So now you have

$$\large z = \frac{-14xy}{w}$$

Plug in the value you have and the values you want...to solve for 'z'
x = 3
y = 4
w = 6

$$\large z = \frac{-14(3)(4)}{6}$$

nikato · Answer

correct
so now your equation is
$$z=\frac{ -14xy }{ w }$$
now use this formula by pluggin in your known values to solve for z

anonymous · Answer

Ah thank you guys! ;v; I know how to solve these now

nikato · Answer

you're welcome!