ST = XY RST is equal to TXY. So, ST is the second and last letters for RST. the second and last letter of TXY are XY. Therefore, ST=XY. Hope this helps!
To fill in the first column = Every day is 7 dollars, which you have already answered. The second one would be = day 0 = 30 dollars. And then it would be 4$ for days 1 through 10. Hope this helps!
