Given that r = (7,3,9) and v=(3,7,-9), evaluate r + v. A. (-21,-21,81) B. (10,10,0) C. (21,21,-81) D. (-10,-10,0)

   B.  (10, 10, 0)

Step-by-step explanation:

Each component of the sum is the sum of corresponding components:

  r + v = (7, 3, 9) +(3, 7, -9) = (7+3, 3+7, 9-9) = (10, 10, 0)

sine

step-by-step explanation:

answer: the resulting cross section is a rectangle. solution: a plane parallel to the base of a triangular prism will intersect a cross section that is the same shape as its bases. so the cross section is a triangle.

step-by-step explanation: