A^2-12a+36
factor. check by expanding.

     a2 + 6a + 6a + 36

                    a • (a+6)
              
                    6 • (a+6)

                    (a+6)  •  (a+6)
      

   Multiply  (a+6)  by  (a+6) 

The rule says : To multiply exponential expressions which have the same base, add up their exponents.

The product is therefore,  (a+6)(1+1) = (a+6)2 

the answer is d. (1.2, -4.7) on edgn

hope this !