Question

(x+1). (X-4)??? Alguém sabe?

Answer 1

(x+1).(x-4)

Fazendo a distributiva:
$x^{2} -3x-4=0 Resolvendo Bhaskara: x1 = -1 x2= 4$

Answer 2

(X+1) . (X-4)=
X^2-4X+X-4=
X^2-3X-4=

a= 1
b= -3
c= -4
∆= b^2-4.a.c
∆= (-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={4; -1}