Acertain kind of animal weighs about 75 pounds at birth and gains about 2 pounds per day for the first few weeks. determine those days for which the animal's weight is more than 125 pounds. the animal's weight is more than 125 pounds when the animal is more than days old.

25

Let w represent the weight of the animal in pounds, and d the age in days. The problem statement tells us ...

... w = 75 +2d

We want to find d when w > 125.

... 75 +2d > 125 . . . . . substitute the above expression for w

... 2d > 50 . . . . . . . . . subtract 75

... d > 25 . . . . . . . . . . . divide by 2

The animal will weigh more than 125 pounds when it is more than 25 days old.