Question

x ao quadrado =4x +5

Answer 1

x² - 4x+5=0 delta : (-4)²-4.(1).(5) = 16-20 = -4 x = [-(-4)+-raiz(delta)]/[2.(1)] x = (4+-raiz(-4))/2 x = 2+-raiz(-1) Resposta: x = 2+i ou x=2-i.

Answer 2

a= 1 b=4 c=-5 
∆=b²-4a.c 
∆=4²-4.(1).(-5)
∆= 16+20
∆=36 

x=-b±√∆/2.a 
x=4±√36/2.1
x= 4±6/2

x'= 4+6/2=10/2=5 
x"= 4-6/2=-2/2=-1
S{ 5,-1}