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:
solve→y((3×y−5)6=(2×y−1)3+2)
y=−15
3×t−2+t=4−7×t
So
4t-2=-7t+4
4t=-7t+6
11t=6
t=611
+870 
