Question

Which equations show a direct variation between x and y when solved for y?

Choose all answers that are correct.
A -10+y=3x-10
B y=-1/8x
C y+9=9x
D y=4-1

Answer 1

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=-(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