The expression to find the value of y when x is 2, given that y varies directly with x and t is 48 when x is 6, is B) y = 16.
The student is asking which expression can be used to find the value of y when x is 2, given that y varies directly as x and t is 48 when x is 6. To solve for y, you can set up a proportion based on the information given that when x is 6, t (which is the product of x and y in direct variation) is 48. This means that 6*y = 48. From this, we find that y = 48/6 = 8. Now, to find y when x is 2, we use the direct variation relationship y = kx (where k is the constant of proportionality) and the fact that k = 8 to get y = 8 * 2 = 16.
Therefore, the correct expression to find y is B) y = 16.