Question 8200
<font face = "courier new" size = 2>Could someone please help me out with this one?  I am suppose to 
evaluate this expression if a= -2, b = 5, c = -4, and d = 6
`
b^2 - 2bc+c^2 =
`
Here is what I have tried but it really looks wrong to me.
5^ - 2(5)(-4)+ -4^2 = and now I can't even figure out the answer to this.  So I know there has to be a better way and I am hoping someone can show me.
Thanks
`<font size = 3><b>
b<sup>2</sup> - 2bc + c<sup>2</sup>
`
Put (5) in place of b 
`
(5)<sup>2</sup> - 2(5)c + c<sup>2</sup>
`
Put (-4) in place of c
`
(5)<sup>2</sup> - 2(5)(-4) + (-4)<sup>2</sup>
`
Replace (5)<sup>2</sup> by 25
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25 - 2(5)(-4) + (-4)<sup>2</sup>
`
Replace - 2(5)(-4) by + 40
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25 + 40 + (-4)<sup>2</sup>
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Replace + (-4)<sup>2</sup> by + 16
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25 + 40 + 16
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Replace 25 + 40 by 65
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65 + 16
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Replace 65 + 16 by 81
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81
`
Edwin