Let $t$ be TNYWR.

If $\frac{3(x+5)}{4}=t+\frac{3-3 x}{2}$, what is the value of $x$ ?
If $\frac{3(x+5)}{4}=t+\frac{3-3 x}{2}$, then $3(x+5)=4 t+2(3-3 x)$ or $3 x+15=4 t+6-6 x$, which gives $9 x=4 t-9$ or $x=\frac{4}{9} t-1$.

Since the answer to (a) is 9 , then $t=9$ and so $x=\frac{4}{9} t-1=4-1=3$.