Question

Simplifique as expressões abaixo

x(x - 3) - 4(x + 1/2)²

(x - 3)² - (x + 2)² + (x + 3)(x - 1)
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Answer 1

Resposta:

1)

$x(x-3)-4(x+\frac{1}{2} )^{2} =\\ \\ x^{2} -3x-4[x^{2} +2.x.\frac{1}{2} +(\frac{1}{2} )^{2} ]=\\ \\ x^{2} -3x-4(x^{2} +x +\frac{1}{4} )=\\ \\ x^{2} -3x-4x^{2} -4x-4.\frac{1}{4} =\\ \\ x^{2} -3x-4x^{2} -4x-1~~~~agrupe~termos~semelhantes\\ \\ x^{2} -4x^{2} -3x-4x-1=\\ \\ -5x^{2} -7x-1$

2)

$(x-3)^{2} -(x+2)^{2} +(x+3)(x-1)=\\ \\ (x^{2} -2.x.3+3^{2}) -(x^{2} +2.x.2+2^{2} )+(x^{2} -x+3x-3)=\\ \\ x^{2} -6x+9-x^{2} -4x-4+x^{2} -x+3x-3~~~~agrupe~termos~semelhantes\\ \\ x^{2} -x^{2} +x^{2} -6x-4x-x+3x+9-4-3=\\ \\ x^{2} -8x+2$