Question

produtos notáveis me ajudem
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Answer 1

Resposta:

$1\\ \\ a)~(x+7)^{2} =x^{2} +2.x.7+7^{2} =x^{2} +14x+49\\ \\ b)~(a+3)^{2} =a^{2} +2.a.3+3^{2} =a^{2} +6a+9\\ \\ c)~(y+1)(y+1)=(y+1)^{2} =y^{2} +2.y.1+1^{2} =y^{2} +2y+1\\ \\ d)~(3+2b)(3+2b)=(3+2b)^{2} =3^{2} +2.3.2b+(2b)^{2} =9+12b+4b^{2}$

$2\\ \\ a)~(2-x)^{2} =2^{2} -2.2.x+x^{2} =4-4x+x^{2} \\ \\ b)~(a-4)^{2} =a^{2} -2.a.4+4^{2} =a^{2} -8a+16\\ \\ ~c)~(x-y)(x-y)=(x-y)^{2} =x^{2} -2xy+y^{2} \\ \\ d)~(2a-b)(2a-b)=(2a-b)^{2} =(2a)^{2} -2.2a.b+b^{2} =4a^{2} -4ab+b^{2}$

$3\\ \\ a)~(m+2)(m-2)=m^{2} -2^{2} =m^{2} -4\\ \\ b)~(x+5)(x-5)=x^{2} -5^{2} =x^{2} -25\\ \\ c)~(2y+4)(2y-4)=(2y)^{2} -4^{2} =4y^{2} -16\\ \\ d)~(5b-7)(5b+7)=(5b)^{2} -7^{2} =25b^{2} -49$