Answer:
19 weeks
Explanation:
You'll be looking for an equation the form of
y=mx+b
Given:
b = $103.50
m = $5.50
x = ? (where x is in weeks)
Next, set y = 0
--> mx+b = 0
Rearrange
x = (-b/m)
Plug in b and m:
x = (-(-103.5)/5.5) = 18.818
Rounding up, it will Martha 19 weeks to save enough money.