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Will someone show me how to arrive at the solutions to these problems please? We have to use the quadratic formula to solve i believe.

(x-1)^2 = 8


x / x - 1 + 1/x = 2

Thanks in advance, im hoplessly lost currently

2006-10-03 16:42:14 · 6 answers · asked by poohntao 2 in Science & Mathematics Mathematics

6 answers

(x - 1)² = 8

(x - 1)² = √8

(x - 1)² = √4 √2

(x - 1)² = 2√2

x - 1 = 2√2

x = 1 ± 2√2

2006-10-03 22:04:35 · answer #1 · answered by SAMUEL D 7 · 0 0

OR, if you really want to use the quadratic formula,

1) (x-1)^2 = x^2 - 2x +1 = 8 or x^2 - 2x -7 = 0 --(solve with quadratic formula)

2) Too simple to use the q/f

2006-10-03 23:57:07 · answer #2 · answered by Steve 7 · 0 0

the easiest way to do the first problem is take the square root of both sides and subtract 1 on both sides *but* remember that when you take the square root of a number you get + or - the square root of that number so it would be....

x=(+ or -)sqrt(8) - 1

then do this for the second...
create a least common denominator
(x/x)*x /( x - 1) + [(x-1)/(x-1)]*1/x = 2
x^2/[x^2-x)] + (x-1)/[x^2-x)] = 2
then multiply the least common denominator on both sides
x^2 + x - 1 = 2x^2 - 2x
set equal to zero
x^2 - 3x + 1 = 0
use quadratic formula
x=[3(+ or -)sqrt(3^2 - 4(1)(1))]/2(1)
then solve

sorry this looks really confusing because its on the computer try to write it out on a piece of paper

2006-10-04 00:07:29 · answer #3 · answered by fleisch 4 · 0 0

One at a time... (x-1)^2 = 8 taking the sq root of both sides gives us x-1 = 8^(1/2).. now add 1 to both sides to get...
x=8^(1/2)+1 therefore x=3.828 no quad eq. req'd

x/x-1 +1/x =2 well x/x is 1 right and 1-1 is zero therefore...
1-1+1/x=2
1/x=2
Multiply by x (both sides) to get 2x=1 so x=1/2

2006-10-03 23:48:56 · answer #4 · answered by Larry L 3 · 0 0

step by step for #1

(x-1)=Sqrt(8)

x=Sqrt(8)-1


#2

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

(x^2+x+1)/(x^2+x)=2

at this point, i'd drop it into mathimatica or a similar program i don't have on my computer

2006-10-03 23:49:58 · answer #5 · answered by quelforlor 2 · 0 0

I wish I could but I loaned out the numbers on my keyboard.

2006-10-03 23:45:34 · answer #6 · answered by Anonymous · 0 0

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