Question

descubra o valor de x : (x-2).(x-5) = 0 e (x-1).(x-3) = 0

Answer 1

(x-2)(x-5)=0
x² -5x-2x+10=0
x²-7x+10=0
Δ=(-7)²-4.1.10
Δ=49-40
Δ=9
x=7+/-√9 /2
x=7+/-3/2
x'=7+3/2
(x'=5)
x''=7-3/2
x''=4/2
(x''=2)
     

(x-1)(x-3)=0
x²-3x-x+3=0
x²-4x+3=0
Δ=(-4)²-4.1.3
Δ=16-12
Δ=4
x=4+/-√4 /2.1
x=4+/-2/2
x'=4+2/2= 3
x''=4-2/2=1