The vet told Sarah that her dog should weigh at most 70 pounds. Her dog weighs 106 pounds, so Sarah set a goal that he would lose 4 pounds per week. How many weeks will it take for Sarah's dog to weigh 70 or less?

It will take at least 10 weeks

Step-by-step explanation:

Sarah set a goal that he would lose 4 pounds per week. This means that the rate at which the dog would lose weight is in arithmetic progression. The formula for determining the nth term of an arithmetic sequence is expressed as

Tn = a + (n - 1) d

Where

a represents the first term of the sequence.

d represents the common difference.

n represents the number of terms in the sequence.

From the information given,

a = 106 pounds

d = - pounds (it is losing weight)

n

We want to determine the number weeks will it take for Sarah's dog to weigh 70 or less. Therefore,

70 = 106 - 4 (n - 1)

70 = 106 - 4n + 4

4n = 106 + 4 - 70

4n = 40

n = 40/4 = 10