Question

quais sao as raizes da equaçao x2-3x-4=0?

Answer 1

x² - 3x - 4 = 0

a = 1
b = -3
c = -4

Δ = b² - 4ac
Δ = (-3)² - 4(1)(-4)
Δ = 9 + 16
Δ = 25

x = -b$\frac{+}{-}$√Δ
       -----------
          2a

x = -(-3) $\frac{+}{-}$√25
      ----------
           2

x = 3 $\frac{+}{-}$5
      --------
         2

x' = 3 + 5
       ------
          2

x' = 8
      ---
       2

x' = 4

x" = 3 - 5
       ------
          2

x" = -2
       ---
        2

x" = -1

S = {-1,4}