Question

Resolver essas equações do 2 Grau
x² - 7x + 12 = 0
x² + 5x + 6 = 0
4x² - 6x + 2 = 0

Answer 1

x² - 7x + 12 = 0
a=1 , b -7 , c= +12
▲=b² -4.a.c= (-7)² -4.(1)(+12)= +49 -48= 1

x= ((-b) +ou- √▲)/2.a
x= (-(-7) +ou-√1)/2.1
x= (+7 +ou- 1)/2
x'=(7+1)/2 = 8/2=4
x"=(7-1)/2- 6/2=3
S= 4 e 3

x² + 5x + 6 = 0
a=1 ,b= +5 , c= +6
▲= b² -4.a.c= 5² -4.(1)(+6)= 25 -24= 1

x= ((-b) +ou- √▲)/2.a
x= (-(+5) +ou- √1)/2.1
x= (-5 +ou- 1)/2
 x'=(-5 +1)/2= -4/2=-2
x"= (-5 -1)/2= -6/2=-3
S= -2 e -3

4x² - 6x + 2 = 0 : 2
2x² -3x +1=0
a=2, b = -3 e c= +1
▲= b²  -4.a.c= (-3)²  -4.(2).(1)= 9-8=1

x= ((-b) +ou- √▲)/2.a
x= (-(-3) +ou- √1)2.1
x= (+3 +ou- 1)/2
x'=(3+ 1)/2= 4/2= 2

x"=(3-1)/2= 2/2= 1
S= 2 e 1