Sagot :
Step-by-step explanation:
[tex]y = kxz \\ \\ k = \frac{y}{xz} \\ \\ \frac{45}{18(10)} = \frac{y}{20(30)} \\ \\ \frac{45}{180} = \frac{y}{600} \\ \\ 180y = 45(600) \\ \\ 180y = 27000 \\ \\ \frac{180y}{180} = \frac{27000}{180} \\ \\ y = 150[/tex]