Question

Resolva as equações de 2o grau 1) x² - 4x - 5 = 0 2) -x² + x + 12 = 0 3) -x² + 6x - 5 = 0 4) 6x² + x - 1 = 0 5) 3x² - 7x + 2 = 0​

Answer 1

Resposta:

Explicação passo a passo:

1) a=1, b= -4, c= -5

x= -b±√b²-4ac/2

x= -(-4)±√(-4)²-4.1.(-5)/2

x=4±√16+20/2

x=4±√36/2

x=4±6/2

x=4+6/2. x=10/2. x=5

x=4-6/2. x= -2/2. x= -1

2) a= -1, b=1, c=12

x= -b±√b²-4ac/2

x= -1±√1²-4.(-1).12/2

x= -1 ±√1-48/2

x= -1±√-47/2 x=∅

3) a= -1, b=6, c= -5

x= -b±√b²-4.a.c/2

x= -6±√6²-4.(-1).(-5)/2

x= -6±√36-20/2

x= -6±√16/2

x= -6±4/2

x= -6+4/2. x= -2/2. x= -1

x= -6-4/2. x= -10/2. x= -5

4) a=6, b=1, c= -1

x= -b±√b²-4ac/2

x= -1±√1²-4.6.(-1)/2

x= -1±√1+24/2

x= -1±√25/2

x= -1±5/2

x= -1+5/2. x= 4/2. x=2

x= -1-5/2. x= -6/2. x= -3

5) a=3, b= -7, c=2

x= -b±√b²-4ac/2

x= -(-7)±√(-7)²-4.3.2/2

x= 7±√49-24/2

x= 7±√25/2

x=7±5/2

x=7+5/2. x=12/2. x=6

x=7-5/2. x=2/2. x=2