Question

x²-2x=x+4 conta do segundo grau​

Answer 1

Resposta:

S={( -1 , 4)}

Explicação passo-a-passo:

x²-2x=x+4

x²-2x-x-4=0

x²-3x-4= 0

a=1 b=-3 c=-4

∆=b²-4.a.c ∆= (-3)²-4.(1).(-4) ∆=9+16

∆=25

x'=[-(-3)+√25]/2.(1) x'=[3+5]/2 x'=8/2

x'=4

x"=[-(-3)-√25]/2.(1) x"=[3-5]/2 x"=-2/2

x"=-1

Answer 2

x² - 2x = x + 4

x² - 2x - x - 4 = 0

x² - 3x - 4 = 0

A= 1

B= - 3

C= - 4

∆= b² - 4ac

∆= ( - 3)² - 4 • 1 • ( - 4)

∆= 9 + 16

∆= 25

x= - b ± √∆/2a

x= - ( - 3) ± √25 / 2 • 1

x= 3 ± 5/2

x'= 3 + 5/2 = 8/2 = 4

x"= 3 - 5/2 = - 2/2 = - 1

S= ( - 1 , 4)