agentkronus
agentkronus agentkronus
  • 02-03-2015
  • Mathematics
contestada

Find x when P = 21.

P = x(x - 1) / 2

Respuesta :

konrad509
konrad509 konrad509
  • 02-03-2015
[tex]21=\dfrac{x(x-1)}{2}\\ 42=x^2-x\\ x^2-x-42=0\\ x^2+6x-7x-42=0\\ x(x+6)-7(x+6)=0\\ (x-7)(x+6)=0\\ x=7 \vee x=-6[/tex]
Answer Link

Otras preguntas

Brittany says that to determine the distance between 180 and 34, you can just subtract 180 - 34. will subtracting the two numbers without determining the absol
Lynn wants to serve hamburgers at her birthday party if hamburger buns are sold in packages of 8 and hamburger patties are sold packages of 6 what is the least
The windows were all broken in the middle of the night which statement correctly describes the voice of this sentence
what is the begining of a river called
Muscular flexibility is one component of physical fitness. true false
Could you please help me
Rewrite with a direct object pronoun. Sarah va a comprar las entradas mañana. Sarah va a comprarlas mañana Sara va las a comprar mañana Las va a compr
which plants do siamangs rely on most as a source of their food
which natural resource is not a major export for canada
what is p(2) given p(n)=6-2|1 + n|