Question

qual a resposta de x²=7x-12

Answer 1

x² = 7x - 12
x² - 7x + 12 = 0
x² - 3x - 4x + 12 = 0
x(x - 3) - 4.(x - 3) = 0
(x - 3).(x - 4) = 0

x - 3 = 0
x = 3

x - 4 = 0
x = 4

R.: x = 3 e x = 4

Báscara:

x² - 7x + 12 = 0
a = 1; b = - 7; c = 12
Δ = b² - 4ac
Δ = (-7)² - 4.1.12
Δ = 49 - 48
Δ = 1

x = - b +/- √Δ         - (-7) +/- √1
      ---------------- = ------------------
             2a                  2.1

x = 7 + 1
      -------- = 8/2 = 4
         2

x =   7 - 1
      --------- = 6/2 = 3
          2

R.: x = 4 e x = 3