Answer:
36th weeks
Explanation:
Kelsey has saved $35 to buy a video game worth $390.
She plans to save additional $10 per week.
Let w represents number of week.
Let s represents total saving in w weeks.
Addition saving per week = $10
In w weeks saving = 10w
Previous saving amount = $35
Total saving in w week, s = 35 + 10w
Expression which represents total saving in w weeks
s = 35 + 10w
Now find number of weeks to save $390
So, put s=390 and solve for w
35 + 10w = 390
10w = 390 - 35
w = 355÷10
w = 35.5
Hence, Kelsey will save $390 in 36th weeks.