Question

Qual o valor de x nas questões 4 e 5?

Answer 1

4/ 5 = 6 / x = 4x = 30               

                      x = 30 / 4 = 7,5



6 / 8 = 3 / x + 2 = 24 = x² + 2x               Δ = 4 + 96
 x² + 2x -24 = 0                                      Δ = 100
                                                              Δ  = 10                       
   x ' = 2 + 10 / 2 = 12 / 2 = 6
  x" = 2 - 10 / 2 = - 8 / 2 = - 4

  s (  6 , - 4 )