We will determine if they are equivalent or not as follows:
a.
![30(18a-6b)=540a-180b](https://img.qammunity.org/2023/formulas/mathematics/college/42pe087jhqbu1gmsxmmmond9brm5ohm0as.png)
![\begin{cases}(540)/(48)=(45)/(4) \\ (180)/(36)=5\end{cases}](https://img.qammunity.org/2023/formulas/mathematics/college/py1xdeu0wedal46nx27ij6eomsmqyaokez.png)
We can see that they are not a factor from the expression given, so NO.
b.
![12a+36(a-b)=12a+36a-36b=48a-36b](https://img.qammunity.org/2023/formulas/mathematics/college/z0p6z6bbtswf8u2d61ppa5w83cpz0dwky0.png)
When we expand we can see that they are equivalent.
c.
![12(3a+a-3b)=12(4a-3b)=48a-36b](https://img.qammunity.org/2023/formulas/mathematics/college/p7lx526oaedfnveuqypl5ukemb48wp7r2q.png)
When we expand we can see that they are equivalent.
d.
![4(10a+2a-9b)=4(12a-9b)=48a-36b](https://img.qammunity.org/2023/formulas/mathematics/college/wiphdx6rxptsgllnv5xm4c8d89fbwghmoj.png)
When we expand we can see that they are equivalent.