Y = x squared + 4x - 16
Find the vertex of the parabola by completing the square

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

Can someone check if i did this right since i really want to make sure it’s correct. if you do you so much

The perimeter of a rectangle is 42 inches. if the width of the rectangle is 6 inches, what is the length