Is this right? ? we are learning ‘applying systems of equations’

Ahomeowner plans to hang wallpaper on one wall of a bedroom that is 10 feet long if a stripe of wallpaper is 20 inches wide and stripes or hung vertically how many stripes on wall paper with the homeowner required

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

What are the exclude value of mn+3m