Answer:
a) y = 5x
b) y = 60
Step-by-step explanation:
Since, y is directly proportional to x when y=30, x=6
[tex] \therefore \: y \: \alpha \: \: x \\ \therefore \: y = kx ...(1) \\ plug \: y = 30 \: and \: x = 6 \: in \: eq \: (1)\\ 30 = k \times 6 \\ k = \frac{30}{6} \\ k = 5 \\ plug \: k = 5 \: in \: (1) \\ y = 5x....(2) \: (required \: equation) \\ plug \: x = 12 \: in \: eq \: (2) \\ y = 5 \times 12 \\ \huge \red{ \boxed{y = 60}}[/tex]