Answer:
Li Jing's formula i.e.
is right.
Step-by-step explanation:
Considering the sequence

A geometric sequence has a constant ratio r and is defined by





So, the sequence is geometric.
as



so



Therefore, Li Jing's formula i.e.
is right.
Answer:
x=8
Step-by-step explanation:
Those angles are supplementary so:
140+5x=180
5x=40
x=8
Answer: He spends more time trading stickers by 15 minutes.
Step-by-step: 1 hour is 60 minutes. So 2 hours is 120 minutes. 120 minutes plus his 20 minutes is 140 minutes. Subtract it from his homework time and he spends 15 more minutes trading stickers.
Ten thousands
if you're speaking of place value?
A) x=5+/-73 is the answer I think