SOLUTION: Find all pairs (a,b) such that 2a+b=12 and ab=3

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Question 842990: Find all pairs (a,b) such that 2a+b=12 and ab=3
Answer by josgarithmetic(39617) About Me  (Show Source):
You can put this solution on YOUR website!
b=12-2a;
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ab=a%2812-2a%29=3
12a-2a%5E2=3
-2a%5E2%2B12a-3=0
2a%5E2-12a%2B3=0
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Discriminant=144-4%2A2%2A3=144-24
Discriminant=120
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a=%2812%2B-+sqrt%28120%29%29%2F4
a=%2812%2B-+2sqrt%2830%29%29%2F%282%2A2%29
a=%286%2B-+sqrt%2830%29%29%2F2
highlight%28a=3%2B-+%281%2F2%29sqrt%2830%29%29
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Use the found values for a to find that of b. Start with b=12-2a. You COULD use ab=3 if you want; which way is YOUR choice.