Answer: y = (5/2)x
Explanation:
y varies directly with x implies that y∝x
To turn y∝x to a full equation, introduce a constant k to the right hand side.
Therefore, y = kx
Given that x is 4 and y is 10, substitute x and y in the equation above.
Then, 10 = 4k
4k = 10
k = 10/4
k = 5/2
Since k = 5/2, then the equation y = kx becomes,
y = (5/2)x