Drag the tiles to the correct boxes to complete the pairs. Not all tiles will be used. Match each system of equations to its graph.

To answer the query above, square the binomial. First step in doing so is to square the first term. Then, multiply 2 to the product of the terms. Lastly, square the second term. 
  
                                          (r + s)^2 = r^2 + 2rs + s^2

Thus, the answer is letter B.