If y varies directly as x, and y is 48 when x is 6, which expression can be used to find the value of y when x is 2?

Direct variation is of the form y=kx, where k is the constant of variation.  We are given the point (6,48) so we can solve for k:

48=6k  divide both sides by 6

8=k, so the equation is:

y=8x, then when x=2

y=8(2)

y=16