Question

Saberiam me responder?
2x (4x-1)=21

X (2x-1)+6=4 (x+1)

Answer 1

Resposta:

2x (4x-1)=21

8x^2-2x=21

8x^2-2x-21=0

delta=b^2-4.a.c

x= -b+- raiz de delta/ 2.a

a=8

b=-2

c=-21

resolvendo direto:

delta= 766

x'= +2+- 27.67/2.8

x'=+2+27,67/16

x'=29,67/16

x'=1.85

x"=2-27,67/16

x"=-25,67/16

x"= -1,60

B) 2x^2-x+6=4x+4

2x^2-x+6-4x-4=0

2x^2-5x+2=0