Answer:
Andre have more money after 4 weeks and after 6 week they have same amount of money.
Step-by-step explanation:
When Andre =100 then Elena =10.
After 4 week,
Andre = 100+(5*4)=100+20=120
In this time Elena = 10+(20*4) =10+80 = 90
After more 2months Andre have more 5+5=10
Then his total balance will be 120+10=130.
Than Elena after 2 week have 20+20=40.
Then her total balance will be 90+40=130.
That's mean 4 weeks+ extra 2 weeks total 6 weeks
It's answer will be 36x10^5
As we have
(4x10^10)(9x10^-5)
All terms of this expression are being multiplied
So we will solve it in two parts, simple terms and terms having powers
(4x9)(10^10x10^-5)
As we know when same terms having some powers are multiplied, their powers are added
(36)(10^(10-5))
(36)(10^5)
So it will become
36x10^5