If (A-B-C+D = 12) and (A+B-C-D = 6), what is the value of (B-D)^2? Choose the correct choice:
A) 4.
B) 9.
C) 12.
D) 16.
E) 64.
EQ1: A - 9. - C + D = 12   EQ2: A + 9. - C - D = 6   (1) Subtract EQ1 from EQ2   A - 9. - C + D = 12   - A +9. - C - D = 6   ------------------------   -29. + 2D = 6   (2) Simplify   -9. + D = 3   9. - D = -3   (9.-D)^2 = (-3)^2 = 9   My answer: 9.
<result>B</result>
If (A-B-C+D = 12) and (A+B-C-D = 6), what is the value of (B-D)^2?