We will determine if they are equivalent or not as follows:
a.
[tex]30(18a-6b)=540a-180b[/tex][tex]\begin{cases}\frac{540}{48}=\frac{45}{4} \\ \frac{180}{36}=5\end{cases}[/tex]
We can see that they are not a factor from the expression given, so NO.
b.
[tex]12a+36(a-b)=12a+36a-36b=48a-36b[/tex]
When we expand we can see that they are equivalent.
c.
[tex]12(3a+a-3b)=12(4a-3b)=48a-36b[/tex]
When we expand we can see that they are equivalent.
d.
[tex]4(10a+2a-9b)=4(12a-9b)=48a-36b[/tex]
When we expand we can see that they are equivalent.
