SOLUTION: a^2-2a-48=0

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Question 575948: a^2-2a-48=0
Found 2 solutions by nerdybill, josmiceli:
Answer by nerdybill(7384) About Me  (Show Source):
You can put this solution on YOUR website!
a^2-2a-48=0
factoring the left:
(a+6)(a-8)=0
a = {-6, 8}

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
+a%5E2-2a-48=0+
+a%5E2+-+2a+=+48+
Complete the square:
Take 1/2 of the coefficient of +x+,
square it and add it to both sides
+a%5E2+-+2a+%2B+%28-2%2F2%29%5E2++=+48%2B+%28-2%2F2%29%5E2+
+a%5E2+-+2a+%2B+1+=+48+%2B+1+
+%28+a+-+1+%29%5E2+=+7%5E2+
Take the square root of both sides
+a+-+1+=+7+
+a+=+8+
and, also, taking the negative root,
+a+-+1+=+-7+
+a+=+-6+
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+a+-+8+=+0+
+a+%2B+6+=+0+
+%28+a+-+8+%29%2A%28+a+%2B+6+%29+=+0+