Note: Consider the equation is
instead of
.
Given:
The graph of
goes through A(4,-80).
To find:
The value of k.
Solution:
We have,

It is passes through the point A(4,-80). It means, the point satisfy the equation.
Putting x=4 and y=-80, we get

Divide both sides by 4.


Therefore, the value of k is -20.