The formula for direct variation is \(y=kx\) where \(k
ot=0\).
\(-10+y=3x-10\\
y=3x \Rightarrow \text{it's a direct variation}\\\\
y=-\dfrac{1}{8}x \Rightarrow \text{it's a direct variation}\\\\
y+9=9x\\
y=9x-9 \Rightarrow \text{it's not a direct variation}\\\\
y=4-1 \\
y=3 \Rightarrow \text{it's not a direct variation}\)
A and B
