Explain why it doesn't matter what letter or symbol is used to find an unknown number.

Muujiunc utc allswers aduve is not cutel.(1 point) solve the system using the substitution or elimination method| 2x – 6y = 14,-3.x +9y = –21.how many solutions are there to this system? o a. noneob. exactly 1oc. exactly 2od. exactly 3o e. infinitely manyof. none of the aboveif there is one solution, give its coordinates in the answer spaces below.if there are infinitely many solutions, enter x in the answer blank for x and enter a formula for y in terms of r in the answer blank for y.if there are no solutions, leave the answer blanks for i and y empty.=xy=1note: in order to get credit for this problem all answers must be correct.