Question

A x² +×-20=0 S={-5,4}

B x²-6x=0 S={0,6}

C x²-9=0 S={+/- 3}​

preciso das conta​

Answer 1

Explicação passo-a-passo:

A ∆= 1² - 4 × 1 (-20)

∆=1 + 80

∆= 81

x=

$\binom{ - 1 + - \sqrt{81} }{2 \times 1}$

x'=

$\binom{ - 1 - 9}{2} = \binom{ - 10}{2} = - 5$

x"=

$\binom{ - 1 + 9}{2} = \binom{8}{2} = 4$

B ∆= (-6)² - 4 × 1 × 0

∆= 36

x=

$\binom{6 + - \sqrt{36} }{2 \times 1}$

x'=

$\binom{6 - 6}{2} = 0$

x"=

$\binom{6 + 6}{2} = \binom{12}{2} = 6$

C ∆=0² - 4 × 1 × (-9)

∆= 36

x=

$\binom{0 + - \sqrt{36} }{2 \times 1}$

x'=

$\binom{0 - 6}{2} = \binom{ - 6}{2} = - 3$

x"=

$\binom{0 + 6}{2} = \binom{6}{2} = 3$