The value of x and y vary directly and one pair of values are given write an equation that relates x and y simplify completely X=-5 y=10

Since the value of y is the product of -5 and -2, the eqeuation must be as follows:
[tex]\begin{gathered} 10=-2(-5) \\ y=-2x \end{gathered}[/tex]This means that each value of y is obtained by multiplying the value of x by -2. Therefore, the missing value is -2.