Question

Resolva as equações abaixo:​

Answer 1

Aplicando a fórmula de bhaskara podemos resolver todas.

$\frac{-b\frac{+}{-} \sqrt{b^{2}-4ac } }{2a}$

a)

$\frac{-1\frac{+}{-} \sqrt{1^{2}-4.(-1).2 } }{2.(-1)}\\\\\frac{-1\frac{+}{-} \sqrt{9 } }{-2}\\\\x' = -1\\x'' = 2$

b)

$\frac{-(-36)\frac{+}{-} \sqrt{(-36)^{2}-4.6.54 } }{2.6}\\\\\frac{36\frac{+}{-} \sqrt{0} }{12}\\\\x' = x'' = 3$

c)

$\frac{-18\frac{+}{-} \sqrt{18^{2}-4.2.40 } }{2.2}\\\\\frac{-18\frac{+}{-} \sqrt{4} }{4}\\\\x' = -4\\x'' = -5$

d)

$-x^{2} + 1 - 8x +2 + 5x^{2} = 0\\4x^{2} -8x +3 = 0\\\\\frac{-(-8)\frac{+}{-} \sqrt{(-8)^{2}-4.4.3 } }{2.4}\\\\\frac{8\frac{+}{-} \sqrt{16 } }{8}\\\\x' = \frac{12}{8} = 1,5\\\\x'' = \frac{4}{8} = 0,5$

e)

$-3 -9x^{2} -14x +7x^{2} +19x -1= 0\\-2x^{2} + 5x-4 = 0\\\\\frac{-5\frac{+}{-} \sqrt{5^{2}-4.(-2).(-4) } }{2.(-2)}\\\\x' = \frac{-5+ \sqrt{-7 } }{-4}\\x'' = \frac{-5- \sqrt{-7 } }{-4}$