<PRE><B>Question 759039</B>
p^2+q^2=85, p-q=1,then p^2-q^2=?
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p = 1+q
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Equation:
(1+q)^2 + q^2 = 85
1 + 2q + 2q^2 = 85
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2q^2 + 2q - 84 = 0
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q^2 + q - 42 = 0
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Factor:
(q+7)(q-6) = 0
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q = 6 or q = -7
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Solve for &quot;p&quot;
p - q = 1
If q = 6, p = 7
If q = -7, p = -6
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p^2-q^2=?
 
P^2 - q^2 = 6^2-7^2 = -13
OR
p^2 - q^2 = 7^2 - 6^2 = 13
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Cheers,
Stan H.
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