Question

calcule o valor da expressao x!/ (x-2)! =12

Answer 1

Resposta:

x!/ (x-2)! =12

x*(x-1)*(x-2)!/ (x-2)! =12

x*(x-1)=12

x²-x=12

x²-x-12=0

x'=[1+√(1+48)]/2 =(1+7)/2=4

x''=[1-√(1+48)]/2 =(1-7)/2<0 , ñ existe fatorial negativo

resposta x= 4