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The formula for (a-b)^2 is a^2-2ab+b^2.
(x-2)^2=x^2-2*x*(-2)+4
=x^2+4x+4

I solved this. Why is not correct to take the second number negative? I mean, the solution for the exercise is x^2-4x+4. Why is it negative instead of positive?

Respuesta :

whitesoxlady
Don't forget negative x negative = positive and negative + negative is still negative
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