Respostas

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2014-08-15T13:12:35-03:00
A) (5x - 1) (5x + 1)

    25 x^{2} + 5x - 5x - 1
    25 x^{2} -1

b) (a+b) (a+b)
    a^{2} + ab + ab +  b^{2}
     a^{2} + 2ab +  b^{2}

c) (2 x^{2} - 3x - 6) (5x - 2)
    10 x^{3} - 4 x^{2}  - 15 x^{2} + 6x - 30x +12
    10 x^{3} - 19 x^{2} - 24x + 12

d) (2a +  \frac{3}{5}b ) (a -  \frac{1}{2} b)
    2 a^{2} -  \frac{2}{2}ab +  \frac{3}{5}ab -  \frac{3}{10} b^{2}
    2 a^{2}  - \frac{10ab + 6ab}{10} +  \frac{3}{10} b^{2}
    2 a^{2} -  \frac{2}{5} ab -  \frac{3}{10} b^{2}


2 5 2