I might be misreading something here but if:
x^5+243=0 subtract 243 from both sides
x^5=-243 raise both sides to the 1/5 power (or take the fifth root of both sides)
x=-3
So there is only one solution, x=-3
You can't divide by 0. It is impossible.
The square root of 142 is 11.916
3.14 by 3.57 just divide those numbers by 14 and round to the hundredths place
The answer to t is t= 21/2