Procedure:
1. Make y the subject of the formula in all the given equations
2.Then compare the relationship between x and y for direct variation.
[tex]\begin{gathered} -10+y=3x-10 \\ \text{Adding 10 to both sides, we get, } \\ y=3x \end{gathered}[/tex]In y = 3x, the variation of y and x is a DIRECT VARIATION.
B:
[tex]y=\frac{1}{8}x[/tex]The variation of x and y in equation B is DIRECT VARIATION
For the equation in option C, that is,
[tex]\begin{gathered} y+9=9x \\ y=9x-9 \end{gathered}[/tex]The variation in equation C is a DIRECT VARIATION.
But in equation D, y does not vary with x, that is, y has no direct variation with x.
Therefore, the correct answers are options A, B, and C.
