670,903,752,021,072,936,960 (short numeric scale, official in every English-speaking countries)
670,000,903,000,752,000,021,000,072,936,960, (long scale, officially used in UK until 1972)
This is just some "brain food" as Melody said.
Anyway, your answers are perfect.
20/20
Here's your cookie:
$$\underset{\,\,\,\,{\textcolor[rgb]{0.66,0.66,0.66}{\rightarrow {\mathtt{y}}}}}{{solve}}{\left({\frac{\left({\mathtt{3}}{\mathtt{\,\times\,}}{\mathtt{y}}{\mathtt{\,-\,}}{\mathtt{5}}\right)}{{\mathtt{6}}}}={\frac{\left({\mathtt{2}}{\mathtt{\,\times\,}}{\mathtt{y}}{\mathtt{\,-\,}}{\mathtt{1}}\right)}{{\mathtt{3}}}}{\mathtt{\,\small\textbf+\,}}{\mathtt{2}}\right)}$$
$${\mathtt{y}} = -{\mathtt{15}}$$
$${\mathtt{3}}{\mathtt{\,\times\,}}{\mathtt{t}}{\mathtt{\,-\,}}{\mathtt{2}}{\mathtt{\,\small\textbf+\,}}{\mathtt{t}} = {\mathtt{4}}{\mathtt{\,-\,}}{\mathtt{7}}{\mathtt{\,\times\,}}{\mathtt{t}}$$
So
4t-2=-7t+4
4t=-7t+6
11t=6
t=$${\frac{{\mathtt{6}}}{{\mathtt{11}}}}$$
+870 
