Question

If y varies directly as x and y=288 when x=16 determine the value of y when x-13

Answer 1

Y = kx is the direct variation equation
Substitute the x and y that are given to find k then write your new equation in terms of y with the k.

288 = k(16) divide by 16 to find k
18 = k
Now write the new equation
y = 18x

y = 18(13) or y = 18(-13) I'm not sure by what you have typed if that is supposed to be and equal sign or a negative.
y = 234 OR y = -234