Question

Resolva na fórmula de bháskara

(X-3)sobre 2 = 2x (x+7)

Answer 1

(x - 3)   = 2x.(x + 7)
---------
    2

x - 3 = 2.2x.(x + 7)
x - 3 = 4x.(x + 7)
x - 3 = 4x² + 28x
0 = 4x² + 28x - x + 3
0 = 4x² + 27x + 3
4x² + 27x + 3 = 0
a = 4; b = 27; c = 3
Δ = b² - 4ac
Δ = 27² - 4.4.3
Δ = 729 - 48
Δ = 681

x = - b +/- √Δ   = - 27 +/- √681
       -------------    --------------------- 
             2a               2.4

x' = - 27 + √681
      ------------------
              8

x" = - 27 - √681
      ----------------
              8