Respostas

  • Usuário do Brainly
2013-12-08T19:43:14-02:00
a)x²-5x+6=0
Vamos usar a fórmula do Δ
Δ=b²-4.a.c
a=1      b=-5         c=6
Δ=(-5)-4.1.6
Δ=25-24
Δ=1
Agora a fórmula de bhaskara.
x= \frac{-b+- \sqrt{\Delta} }{2.a}
x= \frac{5+- \sqrt{1} }{2.1} \\\\
 x=\frac{5+-1}{2} \\\\
x'= \frac{5+1}{2} \\\\
x'= \frac{6}{2} \\\\
x'=3\\\\
x"= \frac{5-1}{2}\\\\
x" \frac{4}{2}\\\\
x"=2
V=\{3,2\}

b)x²-8x+12=0
a=1         b=-8     c=12
Δ=(-8)²-4.1.12
Δ=64-48
Δ=16
x= \frac{8+- \sqrt{16} }{2.1} \\\\
x= \frac{8+-4}{2}\\\\
x'= \frac{8+4}{2}\\\\
x'= \frac{12}{2}\\\\
x'=6\\\\
x"=\frac{8-4}{2}   \\\\
x"= \frac{4}{2} \\\\
x"=2\\\\
V=\{6,2\}

c)x²+2x-8=0
a=1       b=2         c=-8
Δ=2²-4.1.(-8)
Δ=4-32
Δ=-28
Δ=Ф
V=Ф
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