Question

Resolva as equacoes de 2 grau, usando a Formula de Bhaskara:


A) x . (x+1)=30

B)2x . (4x-2)-4=0

C)(2x-3)²=8x

Answer 1

Resposta:

observe a foto, nela contém todas as resoluções

Explicação passo-a-passo:

foto.

Answer 2

Explicação passo-a-passo:

x . (x+1)=30

x²+x=30

x²+3x-30=0

a=1

b=1

c=-30

∆=b²-4ac

∆=1-4*1*-30

∆=1+120

∆=121

-b±√∆/2a

-1±√121/2*1

-1±11/2

x¹=-1+11/2=10/2=>5

x²=-1-11/2=-12/2=>-6

2x . (4x-2)-4=0

8x²-4x-4=0

Reduzindo

8x²-4x-4=0(÷4)

2x²-x-1=0

a=2

b=-1

c=-1

∆=b²-4ac

∆=(-1)²-4*2*-1

∆=1+8

∆=9

-b±√∆/2a

1±√9/2*2

1±3/4

x¹=1+3/4=4/4=>1

x²=1-3/4=-2/4(÷2)=>-1/2

(2x-3)²=8x

(2x)²-2*2x*3x+3²=8x

4x²-12x+9=8x

4x²-12x-8x+9=0

4x²-20x+9=0

a=4

b=-20

c=9

∆=b²-4ac

∆=(-20)²-4*4*9

∆=400-144

∆=256

-b±√∆/2a

20±√256/2*4

20±16/8

x¹=20+16/8=36/8(÷4)=>9/2

x²=20-16/8=4/8(÷4)=>1/2