Question

After a baby was born, she began to gain weight at a rate of 1.5 pounds per month. The weight of the baby at birth was 12 pounds. Write an equation for W,W, in terms of t,t, representing weight, in pounds, of the newborn baby tt months after birth.

Answer 1

What we know:

The baby gains 1.5 pounds per month.

Its weight at birth is 12 pounds.

Therefore, when looking to find the weight after t time, we have to take the constant and the rate of change and place them into the equation. This means our equation will look something like this:

W(t) = Rate of Change x number of months + weight at birth.

Or

W(t) = 1.5(t) + 12

So if in 4 months we look at the weight, the baby will be:

1.5 (4) + 12 = W(t)

6 + 12 = W(t)

18 = W(t)

After 4 months the baby is 18 pounds.

Answer: W(t) = 1.5(t) + 12

I hope this helps! :)