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 :

The formula for direct variation is [tex]y=kx[/tex] where [tex]k\not=0[/tex].

[tex]-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}[/tex]

A and B