Question

Resolva as equações,nas quais o X representa um número real.

Answer 1

Vamos lá!!


a) 3x^2 -36=0

▲= 0^2 -4.3.-36
▲=0 + 432
▲=432

x=-0+- raiz de 432
÷÷÷÷÷÷÷÷÷÷÷÷÷
2.3

x= 0 + 20,78
÷÷÷÷÷÷÷÷÷ = 20,78/6
6


x= 0 - 20,78
÷÷÷÷÷÷ = -20,78/6
6


b) 18x^2 -2=0


▲= 0^2-4.18.-2
▲= 0+ 144
▲= 144

x= -0+- raiz de 144
÷÷÷÷÷÷÷÷÷÷÷÷
2.18


x= 0+12
÷÷÷÷÷ = 12/36 = 2/6 = 1/3
36


x= 0-12
÷÷÷÷ = -12/36 = -2/6 = -1/3
36



c) x (9x -8) = (x-4)^2 ou (x-4). (x-4)

9x^2 -8x = x^2 -8x + 16

8x^2 -16=0

▲= 0^2 -4.8.-16
▲ = 0 + 512
▲ = 512

x= -0 +- raiz de 512
÷÷÷÷÷÷÷÷÷÷÷÷÷÷
2.8


x= 0+22,62
÷÷÷÷÷÷÷ = 22,62/16
16


x= 0 - 22,62
÷÷÷÷÷÷÷ = -22,62/16
16