If (A-B-C+D = 18) and (A+B-C-D = 4), what is the value of (B-D)^2?
Select: A) 49. B) 8. C) 12. D) 16. E) 64.
EQ1: 49. - B - C + D = 18   EQ2: 49. + B - C - D = 4   (1) Subtract EQ1 from EQ2   49. - B - C + D = 18   - 49. +B - C - D = 4   ------------------------   -2B + 2D = 14   (2) Simplify   -B + D = 7   B - D = -7   (B-D)^2 = (-7)^2 = 49   My answer: 49.
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If (A-B-C+D = 18) and (A+B-C-D = 4), what is the value of (B-D)^2?