What is the sum of the digits in the expansion of (10^36+26/18)

Can someone explain the elimination method to me for this problem?

What term best describes a line and a point that lie in the same plane? a. congruent b. coplanar c. collinear d. equal

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