What is the 4th term in a geometric sequence for which a1=15 and r=1/3

Me because some of question i don’t understand

Evaluate the discriminant of each equation. tell how many solutions each equation has and whether the solutions are real or imaginary. 4x^2 + 20x + 25 = 0

Francis is getting new carpet tiles in his living room and den. his living room and den are connected. he needs to figure out how much carpet he needs and the cost involved. if each tile costs $2.00 per sq ft, how much would it cost to have new tile put in the den? a) $24 b) $36 c) $48 d) $54 plz awnser soon