Can someone please help me with this question.

Thank you.

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

On which number line are -3 and its opposite shown

There are a total of 75 students in the robotics club and the science club. the science club has 11 more students than the robotics club. how many students are in the science club?