help with math?

Question

I need help in solving the equation? With a bit of explanation x^2 - 3x - 4 = 0

Answer 1

try breaking the midle term...

like

x^2-3x-4=0

x^2-4x+x-4=0

x(x-4)+1(x-4)=0

(x+1)*(x-4)=0

either x= -1 or x= 4...

Answer 2

x^2 - 3x - 4 = 0
First factorize the equation.
(x - 4)(x + 1) = 0
In factorizing you need to find two numbers which when multiplied together give 4 , and when added give 3.I do this by :-
4 x 1 = 4
2 x 2 = 4
That is write down all the multiples of '4'.
It will be noticed that '4' and '1' by negative addition (subtraction) will give us '3'. However '2' & '2' will only give '4' or '0' - so it can be discounted.
Next is to find the operational signs.When multiplying the '4' and '1' together the answer is negative '-4' so either '4' or '1' is negative. -4 x 1 = -4 or 4 x -1 = -4.
The middle term is -3x. So if' -4' is added to '1' the answer is ' -4', conversely '4' is added to '-1' the answer is '+3'. So the pair of numbers required is '-4' & '+1'.

(x - 4)(x + 1) = 0
Taking each bracketed term :-
x - 4 = 0
x = 4

x + 1 = 0
x = -1
Hence the two values of 'x' are '4' and '-1'. - SOLVED.!!!!!

Answer 3

well it depends what your trying to find. if your trying to find the possibilities of what x can be then i can help you. The answer would be x=4 or x=-1.

you have to remember the general form for quadratic equations(quadratic meaning there is a squared number in it)
the form is ax^2-bx-c=0. so your first step is to find what a, b , and c are. when you use the formula you see that a is 1 since there is no coefficient(number before the variable). b is -3 since -3 is before the variable x. and c =-4. now that you have those you plug it in to the quadratic formula.

the quadratic formula is a bit hard to type so if you don't know it i can send you a link. but after you plug the a, b , and c into this formula you will get 4 and -1.

I know the answer was a little long but with a bit of practice these problems will become second nature to you

Answer 4

This is a quadratic equation of the form AX^2 + BX + C = 0. A,B and C are the coefficients. In the equation, A=1, B=-3 and C=-4. The solution of such an equation is: (B +/- SQRT(B^2 - 4AC))/2A. Substitution yields (3 +/- SQRT(9 + 16))/2 , or (3+5)/2 and (3-5)/2. This results in X=4 or X=-1. The equation itself is simplified to (x-4)(x+1).

Answer 5

Ok so you're factorising the quadratic right?
So basically you need to find two numbers that multiply to make -4 and add/subtract to make -3.
Once you've done that you put it in brackets, here is an example (it's not the answer to your equation):
(x - 2) (x + 6)

This is weird because I've been doing the exact same thing for maths AS level today. It's tricky =/ Hope it helps, anyway.

Answer 6

x^2 - 3x - 4 can be factored as follows:

x^2 - 3x - 4 = 0.
(x - 4) (x + 1) = 0.

x = 4 or -1.

Answer 7

x= -1 or 4

you use something called the reverse of FOIL (First Outer Inner Last) to split the equation into (x+1)(x-4)=0 and then solve each x-4=0, x+1=0 therefore getting x= -1 or 4

if you don't know how to normally use FOIL, here's a handy web site http://www.algebrahelp.com/lessons/simplifying/foilmethod/pg2.htm

Answer 8

Factor.
You get (x - 4)(x + 1) = 0
which means x = 4, -1

Answer 9

use the quadratic equation, the answer is x=4 and x=-1.

Answer 10

i think the answer is 4 and -1 . plug it in and you'll see.

You have to Factor.

You get (x - 4)(x + 1) = 0
which means x = 4, -1