f(x) = 8x^2 + 8x + 7 = 0
8x^2  8x  7 = 0
(ax + b)^2 = (ax)^2 + 2abx + b^2
(x√(8))^2+2(√(8))(√(8)/2)x+(√(8)/2)^2(√(8)/2)^27=0
(x√(8)√(8)/2)^2  (√(8)/2)^2  7 = 0
8(x1/2)^2  (8/4)  7 = 0
8(x1/2)^2 = 9
(x1/2)^2 = 9/8 = 3*3*2/2*2*2*2
x1/2 = 3√(2)/4
x = 1/2 ± 3√(2)/4
The only answer with pairs whose average is 1/2 is A.
2/9/2014

Steve S.
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