3. elizabeth opened a library with 19,000 books in the year 1998. the number of books increases at a rate of 6.49% each year. use a graph to predict the number of books in 2020.
a) ≈ 71,160
b) ≈ 75,779
c) ≈ 80,697
d) ≈ 66,824

The function a represents the cost of manufacturing product a, in hundreds of dollars, and the function b represents the cost of manufacturing product b, in hundreds of dollars. a(t) = 5t + 2 b(t) = 7t - 2t +4 find the expression that describes the total cost of manufacturing both products, a(t) + b(t). a. 7t^2 - 7t + 2 b. 7t^2 + 3 +6 c. 7t^2 + 7t - 6 d. 7t^2 - 3t + 6