[tex]y \: \alpha \: x[/tex]
Let c be the constant
[tex]y = cx \\ 16 = c4 \\ c = \frac{16}{4} \\ c = 4[/tex]
[tex]y = cx \\ y = 4 \times ( - 2) \\ y = ( - 8)[/tex]
Answer:
y = 4x
Step-by-step explanation:
Given y varies directly with x then the equation relating them is
y = kx ← k is the constant of variation
To find k use the condition y = 16 when x = 4 , then
16 = 4k ( divide both sides by 4 )
4 = k
y = 4x ← equation of variation
When x = - 2 , then
y = 4 × - 2 = - 8
