Suppose y varies inversely as x, if y = 7 when x = 6
then find y when x = -21.
we know that
A relationship between two variables, x, and y, represent an inverse variation if it can be expressed in the form
y*x=k
where
k is the constant of proportionality
step 1
Find the value of k
we have
y=7, x=6
k=7*6
k=42
the equation is
y*x=42
step 2
For x=-21
substitute
y*(-21)=42
y=42/(-21)
y=-2