Well we would need to see some type of graph in order to help you find the slope.
Answer:
Take the number of weeks as x
12x = 544 - 100
x =444/12
x = 37
Thus it would take her 37 weeks to buy her a laptop
ANSWER

EXPLANATION
The general term for the sequence is

To find the 55th term, we have to substitute

in to the general term and simplify.
This implies that,




Therefore the 55th term is 161.