Question

resolva as seguintes equações do 2 grau a) x²-7=0 b) x²+5x=0 c)5x²+x=0

Answer 1

Boa noite!
a)
x²-7=0
x²=7
x = √7

b)
x²+5x = 0
a=1, b=5, c=0
Δ = b²-4ac
Δ = 5²-4.1.0
Δ = 25-0 = 25
X = -b+-√Δ/2a
X = -5+-√25/2.1
X = -5+-5/2
X' = -5-5/2 = -10/2 = -5
X" = -5+5/2 = 0/2 = 0

c)
5x²+x=0
a=5, b= 1, c=0
Δ = b²-4ac
Δ = 1²-4.5.0
Δ = 1-0 = 1
X = -b+-√Δ/2a
X = -1+-√1/2.5
X= -1+-1/10
X' = -1-1/10 = -2/10 = -1/5
X" = -1+1/10 = 0/10 = 0

Espero ter ajudado.