Perimeter cm, area square cm

What is the point-slope form of the equation for the line with a slope of -2 that passes through (1,4)?

If f(x)=2x-6 and g(x)=3x+9, find (f-g)(x)

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