7.58 rounded to the nearest tenth place

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

Plz ( true - false) all triangles have interior angles whose measure sum to 90.

What is the perimeter of an isosceles triangle with each leg measuring 2x+3 and the base measuring 6x-2?