164k views
4 votes
Suppose y varies directly with x when x is -2 y is 10 write the equation that relates x and y

Suppose y varies directly with x when x is -2 y is 10 write the equation that relates-example-1
User Odelia
by
7.6k points

1 Answer

1 vote

The form of the equation of the direct proportional is


y=kx

k is the constant of variation

We can find it from the initial values of x and y

Since at x = -2 y = 10, then

Substitute x by -2 and y by 10 to find k


\begin{gathered} x=-2,y=10 \\ 10=k(-2) \\ 10=-2k \end{gathered}

Divide both sides by -2 to find k


\begin{gathered} (10)/((-2))=(-2k)/((-2)) \\ -5=k \end{gathered}

The value of k is -5

Then the equation is


y=-5x

User Jack Ukleja
by
8.2k points

No related questions found

Welcome to QAmmunity.org, where you can ask questions and receive answers from other members of our community.

9.4m questions

12.2m answers

Categories