Hello,



==> 1+r=5==>r=4
3+3r+3r²+3r^3+...+3r^6=3(1+r+r²+...+r^6)=3*(r^7-1)/(r-1)=4^7-1=16383
Answer:
the answer is : 2557421289
9 is the answer for that problem
Okay well 7%, changes into 7/100=0.07 and there are 5 years and you have the beginning amount of 400. So 400×0.07=28. 28×5= 140. So add 140 to the be amount, 400+140=$540.
Answer is $540.
Translation rotation reflection