Respuesta :

Answer:

Step-by-step explanation:

  1. a :
  • x²+x-20 = 0
  • to factor we can calculate the dicriminant
  • we get 81
  • so we have two solutions
  • after factoring using the dicriminant  we get : (x+5) (x-4)
  • so x= 4 or x= -5
  • b :
  • x= 36
  • x-36 = 0
  • x-6²=0
  • (√x+6)(√x-6) = 0
  • √x = 6 or √x= -6 ( impossible for real numbers)
  • x= 6²
  • x= 6
  • d:
  • x= 10x
  • x-10x=0
  • x(1-10) = 0
  • -9x = 0
  • x= 0