Question

If y varies directly with x, and y = 2 when x = −4, what is the value of y when x = 20

Answer 1

Answer:

y = - 10

Step-by-step explanation:

Given that 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 = 2 when x = - 4, that is

2 = - 4k ( divide both sides by - 4 )

= k, that is

k = -  

y = -  x ← equation of variation

When x = 20, then

y = -  × 20 = - 10