Answers

2014-10-29T23:06:37+08:00
I think the solution is written like this: 3^2 a^2 b^2
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2014-10-30T00:05:56+08:00
(x+y+z)²    =  x²+y²+z²+2xy+2xz+2yz
so                 x=3    y=a    z=b
(3+a+b)²=  3²+a²+b² +2 .3a + 2 .3b+2ab
                 = 9+a²+b²+6a+6b+2ab
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