(x + a)(x + b) = x^2 + ax + bx + ab
or
x^2 + (a+b)x + ab
for this problem:
x^2 - 14x + 49
you have to think of sums (a+b) for -14 and factors (ab) for + 49.
what + whatever = -14
and
what * whatever = +49
not a lot of stuff multiplied together = +49 and the first thing to notice is that +49 is a square of 7.... and -7.
Then you notice that -14 would work out really nicely with -7 + -7 cause that's -14
so you try that... (there is some trial and error in factoring)
(x - 7)(x - 7)
that's
x^2 - 7x - 7x + 49
or
x^2 -14x + 49
which is it.
and to make the teacher happy that you can show things in the simplest forms:
Answer: (x - 7)^2
2007-11-07 03:32:08
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answer #1
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answered by Ms. M 3
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since x^2 and 49 are the squares of x and -7 and since -14 x is double and the product of x and -7, X^2-14x+49 is a trinomial square
then x^2 - 14x +49 = (x-7)^2
hope i helped you
2007-11-07 03:46:51
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answer #2
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answered by Anonymous
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x² - 14x + 49
x² - 7x - 7x + 49
= x (x-7) - 7 (x-7)
= (x - 7) (x - 7)
2007-11-07 03:30:24
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answer #3
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answered by A Little Sarcasm Helps 5
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It's a perfect square: (x-7)(x-7) or (x-7)^2
that's it!
2007-11-07 03:15:36
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answer #4
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answered by Marley K 7
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it is a perfect sq
(x-7)^2
2007-11-07 03:15:01
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answer #5
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answered by norman 7
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(x-7)(x-7)
2007-11-07 03:17:28
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answer #6
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answered by Small Victories 4
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(x-7)(x-7)
2007-11-07 03:15:32
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answer #7
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answered by Anonymous
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