If y varies directly with x and y = 25 when x = 5, what is the value of k? how does this work when y = kx?
The value of k when x=5 and y=25 is:
k=5
Direct variation--
Two variables are said to be in direct variation if one variable could be written as a constant multiple of the other variable.
i.e. x and y are said to be in direct variation.
if there exist a constant k such that:
\(y=kx\)
or if x is non-zero then we have:
\(k=\dfrac{y}{x}\)
Here we are given x=5 and y=25
This means that the value of k is:
\(k=\dfrac{25}{5}\\\\i.e.\\\\k=5\)