An irrational number between 5 and 7

If the graphs of the linear equations in a system are parallel, what does that mean about the possible solution(s) of the system? a. there are infinitely many solutions. b. there is no solution. c. there is exactly one solution. d. the lines in a system cannot be parallel.

Look at this pattern ; 1,4,9, number 10000 belongs in this pattern . what’s the place of this number?

Math it's appreciated. (picture provided)