4 hundreds = 4 100s = 4(100) = 400
400 is another way for writing four hundreds.
Hope this helps!
Length of line RS is probably 20 because it’s not smaller than the line it’s parallel to but it’s not equal either so the answer has to be c unless there’s a d that’s between 10-20
common ratio = a4/a3 = a3/a2
8/a3 = a3/18
(a3)^2 = 8 * 18
(a3)^2 = 144
a3 = 12 or a3 = -12
common ratio = 8/12 or common ratio = 8/(-12)
common ratio = 2/3 or common ratio = -2/3
Answer: 12 or -12
