Question

Y varies directly with x, and y = 15 when x = 3. What is the value of x when y = 4?

Answer 1

15/3 = 4/x
5 = 4/x 
so
x = 4/5

Answer 2

The answer would be 1 because 4 times 3 equals 12 and u would add 3 so yeha.