agentkronus
agentkronus
02-03-2015
Mathematics
contestada
Find x when P = 21.
P = x(x - 1) / 2
Respuesta :
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
VER TODAS LAS RESPUESTAS ( 44+ )
Otras preguntas
Elections for representatives to the U.S. House of Representatives are held every two years. Elections take place in November, and there is usually one Republic
Daniel has five bags of coloured sweets. He picks at random a sweet from each bag. The table shows the probability that the sweet he picks from each bag is red.
(3x+12)+x=180 Find the value of x.
what is the original source of the energy stored in fossil fuels
~Help me with this please it’s a math test answer correctly and I will mark as BRANLIEST and I will give you 55 points!!
Square tiles (12 inches by 12 inches) are used to cover a rectangular countertop containing 40 square feet. How many tiles are needed to cover the countertop?
A new car is purchased for 23400 dollars. The value of the car depreciates at 11.5% per year. To the nearest year, how long will it be until the value of the c
What is the cultural heritage of Brazilians
explain the steps for locating the assignment calendar.
Growing food in urban areas could improve full security worldwide
