Lacey went to the fair. She paid $5 for the entrance fee. Each ride ticket cost $0.25. Lacey spent $12.50 at the fair. How many tickets did she buy

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

Precalculus question, image attached.

Express -5 2/5 as an improper fraction.