Answer:
see explanation
Step-by-step explanation:
Given that y is directly proportional to x then the equation relating them is
y = kx ← k is the constant of proportionality
To find k use the condition when y = 30, x = 6
k = =
= 5
y = 5x ← equation of proportionality
When x = 12, then
y = 5 × 12 = 60