Question

Resolva as equações do 2 grau:
a)x2-2=0
b)3x=6x2
c)4x2-25=0
d)(x+1)2=2x
e)4x2=100
f)4x2-4x-3=0
g)(x+3)2=2x(×+7)
h)8x2=0
i)-3x2-2x=-2x
j)4m2-4m-3=0
k)-x2+11x-28=0

Answer 1

a)a=1 b=0 c=-2

x2 = -2

x= +/-√2

S={+/-1,4}

b) a=-6 b=3 c=0

x (-6x+3)=0

x=0// -6x=-3

           x=-3/-6

           x=0,5              S={0,0,5}

c)a=4 b=0 c=-25

4x2= -25

4x= +/-√25

4x= +/-5

x= +/-5/4

x=1,25    S={+/-1,25}

e)a=4 b=0 c=-100

4x2 = 100

4x= +/-√100

4x = +/-10

x= +/-10/4

x= +/-2,5   S={+/-2,5}

f) a=4 b=-4 c=-3

Δ= -4² -4.4.-3

Δ= 16+48

Δ=64

x=-(-4)+/-√64//2.4

x=4+/-8//8

x'= 4+8/8=12/8=1,5

x''= 4-8/8=-4/8=-0,5      S={-0,5,1,5}

j) a=4 b=-4 c=-3

Δ= -4²-4.4.-3

Δ=16+48

Δ=64

x= --4+/-√64/2.4

x=4+/-8/8

x'= 4+8/8=12/8=1,5

x''= 4-8/8=-4/8=-0,5      S={-0,5,1,5}

k) a=-1 b=11 c=-28

Δ= 11²-4.-1.-28

Δ=121-112

Δ=9

x=-11+/-√9/2.-1

x=-11+/-3/-2

x'=-11+3/-2=-8/-2=4

x''= -11-3/-2= -14/-2=7       S={4,7}

não sei se estão certos, mas enfim sksk