Algebra???

Question

Solve by completing the square.
2x^2-4x-11=0

Answer 1

x = 3.549523654

Answer 2

First you must always make the coefficient of x^2 equal to one. So, in your case you must divide throught the equation by 2 to get

x^2 - 2x - 11/2 = 0

Now move the 11/2 to the right side to get

x^2 - 2x = 11/2

Next complete the square on the left side which means you find 1/2 of 2 and square. 1/2(2) = 1. 1^2 = 1

Now add one to both sides of the equation and simplify the right side.

x^2 - 2x + 1 = 11/2 + 1 = 11/2 + 2/2 = 13/2

Rewrite the left side and you get

(x - 1)^2 = 13/2

Next take the square root of both sides and simplify

x -1 = +- sqrt(13/2) = +- sqrt(26)/2

Add 1 to both sides

x = 1 +- sqrt(26)/2 = (2 +- sqrt(26))/2

Now you practice some others following this example. It is necessary that you know how to complete the square and simplify radicals. If you do not know how to do those two things, then you will have a difficult time solving quadratic equations by completing the square. There is a quadratic formula that can be used and will eliminate the necessity of solving by completing the square (which is a pain in the south end going north)

Answer 3

It has been a while since i have done algebra, but it seems to me that this problem isn't going to come out neatly because of the number eleven and becasue of the double negative. But I gave it a shot.
Here it is: 2x^2=4x+11
x^2=(4x+11)/2
x=the square root of (4x+11)/2
I hope this was helpful, if not, sorry I tried.

Answer 4

Cheater! Cheater im telling your teacher. No im kidding i always sucked at math and i barely passed algebra with a c. So im not the one to give an answer on this.

Answer 5

x=[4+/-rt(16+88)]/4
=[4+/-2rt26]/4
=[2+/-rt26]/2

by completing the square
2x^2-4x=11
2(x^2-2x+1-1)=11
2(x-1)^2-2=11
2(x-1)^2=13
(x-1)^2=13/2
x-1=+/-rt(13/2)
x=1+/-rt(13/2)

Answer 6

u can use formula x=-b+sqrt (b^2- 4ac)/2a and
x=-b+sqrt (b^2+4ac)/2a,
where a=2,b=-4 and c=-11.
by putting the values u will get the answer.

Answer 7

I don't know what a " ^ " is. but without that symbol, x= minus 7/4

Answer 8

calculator
!!LOL