Respostas

2013-07-10T21:09:54-03:00
A)(x+3)^2=(x+3)(x+3)=(x^2+3x+3x+9)
=x^2+6x+9

b)(3x-4)^2=(3x-4)(3x-4)=9x^2-12x-12x+16
=9x^2-24x+16

c)(2a+5b)^2=(2a+5b)(2a+5b)
=4a^2+10ab+10ab+25b^2
=4a^2+20ab+25b^2

(2x+y)(2x-y)=4x^2-2xy+2xy-y^2
=4x^2-y^2
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