Suppose y varies directly with x. If y = –4 when x = 8, what is the equation of direct variation? Complete the steps to write the equation of direct variation.
Direct variation is of the form y=kx. We are given the point (8, -4) so we can solve for k, the constant of variation... -4=8k, divide both sides by 8 -4/8=k k=-0.5, so our equation is: y=-0.5x,