Question

5. Reduzca:
(xy+1)(xy+7)+(xy+2)(xy–10)+2(3+xy)(3–xy)
6. Efectúa:
(5+y)(5+3y)–(2+3y)(2+5y)+12(y+1)(y–1)–9

Answer 1

Resolvemos :

5- Reducimos.

(xy + 1)(xy + 7) + (xy + 2)(xy - 10) +2(3+xy)(3 - xy)

(x²y² + 7xy + xy + 7) + (x²y² - 10xy + 2xy - 20) + 2(3² - x²y²)

x²y² + 8xy + 7 + x²y² - 8xy - 20 + 18 - 2x²y²

2x²y² - 2x²y² - 13 + 18

                   5 <=== respuesta.

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6. Efectúa.

(5 + y)(5 + 3y) - (2 + 3y)(2 + 5y) + 12(y + 1)(y - 1) - 9

(25 + 15y + 5y + 3y²) - (4 + 10y + 6y - 15y²) + 12(y² - 1) - 9

25 + 20y + 3y² - (4 + 16y + 15y²) + 12y² - 12 - 9

25 + 20y + 3y² - 4 - 16y - 15y² + 12y² - 12 - 9

                      4y <=== respuesta.