Question

determine o valor de x:

a) x !
--------= 30
(x-2)

b) (x+2)!(x-2)
---------------------=4
(x+1)!(x- 1)!​

Answer 1

Explicação passo-a-passo:

a) x !

--------= 30

(x-2)!

x × (x-1) × (x-2)!/(x-2)!=30

x²-x -30= 0

delta = b²-4ac= 121 = 11

x'= 1 +11/2= 6

x"= 1-11/2= -5 (não convém)

b)(x+2)!(x-2)!

---------------------=4

(x+1)!(x- 1)!

(x+2)×(x+1)! × (x-2)! / (x+1)! × (x-1) × (x-2)!=4

x+2/x-1=4

x+2 = 4x-4

3x=6

x=2