Answer:
225 + 63n for n- a natural number,
set 512=225+63n to find total number of weeks
63=21*3
use n=4 to solve the amount saved in 4 weeks
they wont 60*4=240, 240+12, 252+225=477
how much are the saving a day
what do they need to put up to have enough in 4 weeks
how much a day do the need to save to go in 1 week
etc
Step-by-step explanation:
