Question

resolva equações a seguir.
a)x²-3x+1=0
b)4x²-8x+3=0
c)x²+6x+7=0
d)3x²-5x+2=0
e)-x²+10x-25=0

Answer 1

a) x²-3x=-1
x²-3x+9/4=-1+9/4
(x-3/2)²=5/4
x-3/2=±√5/2
x=3/2±√5/2
x=(3±√5)/2

b)4x²-8x+3=0
x²-2x+3/4=0
x²-2x+1=-3/4+1
(x-1)²=1/4
x-1=±1/2
x=1±1/2

x=3/2

x=1/2

c)x²+6x+7=0
x²+6x+9=-7+9
(x+3)²=2
x+3=±√2
x=-3±√2

d)3x²-5x+2=0
x²-5x/3+2/3=0
x²-5x/3+25/36=-2/3+25/36
(x-5/6)²=1/36
x-5/6=±1/6
x=5/6±1/6

x=1

x=2/3

e)-x²+10x-25=0
x²-10x+25=0
(x-5)²=0
x-5=0
x=5