Question

If x varies inversely with y and x = 8 when y = 6, find y when x = 10

Answer 1

A. y = 5/12
B. y = 4.8
C. y = 7.5
D. y = 40/3

Answer 2

\(\large\color{slate}{ \displaystyle y=\frac{{\rm \color{orangered}{k}}}{ x} }\)

is the equation of an inverse variation.
(where \(\large\color{slate}{ \displaystyle \rm \color{orangered}{k} }\) is the constant of variation).

you are given that:
\(\large\color{slate}{ \displaystyle x=8 }\) (when, ) \(\large\color{slate}{ \displaystyle y=6 }\)

So plug in (8 for x and 6 for y) and solve for \(\large\color{slate}{ \displaystyle \rm \color{orangered}{k} }\).

Answer 3

i got it, B. y = 7.5

Answer 4

right?

Answer 5

~~~~~~~~~~~~~~~~
after you find \(\large\color{slate}{ \displaystyle {\rm \color{orangered}{k}} }\),
you are given that: \(\large\color{slate}{ x=10 }\)

So go ahead and plug in:
1. the value of \(\large\color{slate}{ \displaystyle {\rm \color{orangered}{k}} }\) that you found (instead of \(\large\color{slate}{ \displaystyle {\rm \color{orangered}{k}} }\))
2. 10 for x, (since you want to find the y, when x=10)

you are plugging (again) into: \(\large\color{slate}{ \displaystyle y=\frac{{\rm \color{orangered}{k}} }{x} }\)

Answer 6

no

Answer 7

what have you found your \(\large\color{slate}{ \displaystyle {\rm \color{orangered}{k}} }\) to be ?