Question

x²3x-4=0 alguém pode me ajudar

Answer 1

X²3x-4=0
***para 3x com sinal positivo
X²+3x-4=0
Δ=b²-4ac
Δ=3²-4(1)(-4)
Δ=9+16
x=$\frac{-3 \frac{+}{-} \sqrt{25} }{21}$=25
x= $\frac{-3 \frac{+}{-}5 }{2}$
x'=$\frac{-3+5}{2}$
x'=$\frac{2}{2}$
x=1
x"=$\frac{-3-5}{2}$
x"=$\frac{-8}{2}$
x=-4
***para 3x com sinal negativo
X²-3x-4=0
Δ=b²-4ac
Δ=(-3)²-4(1)(-4)
Δ=9+16
x=$\frac{-(-3) \frac{+}{-} \sqrt{25} }{21}$=25
x= $\frac{<span>3</span> \frac{+}{-}5 }{2}$
x'=$\frac{3+5}{2}$
x'=$\frac{8}{2}$
x=4
x"=$\frac{3-5}{2}$
x"=$\frac{-2}{2}$
x=-1

Answer 2

x² +3x -4 = 0
Δ = b² - 4ac
Δ = 3³ - 4 . 1 . (-4)
Δ = 9+16
Δ = 25

x= -b +-√Δ/2a

x = (-3 +-√25) /2.1
x = (-3 +-5) / 2

x¹= (-3 + 5) / 2...........2/2 = 1
x² =( -3 -5) / 2...........-8/2 = -4

V={1, -4}