How do you solve (x+1)/(x-1)=2/(2x-1)+2/(x-1)?

2 Answers

x=3/2" " the root

x=1" " " the extraneous root

Explanation:

From the give equation, we multiply both sides by the
LCD=(2x-1)(x-1)

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

(2x-1)(x-1)*(x+1)/(x-1)=(2x-1)(x-1)[2/(2x-1)+2/(x-1)]

We simplify to obtain

(2x-1)cancel(x-1)*(x+1)/cancel(x-1)=(2x-1)(x-1)[2/(2x-1)+2/(x-1)]

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

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

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

We expand by multiplication

2x^2-x+2x-1=2x-2+4x-2

Transpose all terms to the left side of the equation

2x^2-x+2x-1-2x+2-4x+2=0

2x^2-5x+3=0

We can solve this now by Factoring method

(2x-3)(x-1)=0

Equate each factor to 0 and solve for the values of x

First factor
2x-3=0

x=3/2

Second Factor
x-1=0
x=1

By checking these values in the original equation, we will find that x=1 is an extraneous root because it will have a division by zero

The value x=3/2 is a Root.

God bless....I hope the explanation is useful.

Mar 26, 2016

x=3/2

Explanation:

Before starting, it is important to note the restrictions in this equation. When the denominator of each fraction is set to not equal 0, the restrictions are:

x-1!=0color(white)(XXXXXXXX)2x-1!=0

x!=1color(white)(XXXXXXXXXX)2x!=1

color(white)(XXXXXXXXXXXXX)x!=1/2

Thus, the restrictions are color(red)(|bar(ul(color(white)(a/a)x!=1,1/2color(white)(a/a)|))).

Solving the Equation
1. Start by finding the L.C.D. (lowest common denominator) for the right side of the equation. Then rewrite the fractions on the right side with the inclusion of the L.C.D.

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

(x+1)/(x-1)=(2color(darkorange)((x-1)))/((2x-1)color(darkorange)((x-1)))+(2color(blue)((2x-1)))/((x-1)color(blue)((2x-1)))

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

2. Simplify the right side of the equation.

(x+1)/(x-1)=(2x-2+4x-2)/((2x-1)(x-1))

(x+1)/(x-1)=(6x-4)/((2x-1)(x-1))

3. Multiply both sides of the equation by color(teal)((x-1)) and color(teal)((2x-1)) to get rid of the denominator.

(x+1)/color(red)cancelcolor(black)((x-1))xxcolor(teal)((2x-1)color(red)cancelcolor(teal)((x-1)))=(6x-4)/(color(red)cancelcolor(black)((2x-1)(x-1)))xxcolor(red)cancelcolor(teal)((2x-1)(x-1))

(x+1)(2x-1)=6x-4

4. Expand the brackets on the left side of the equation.

2x^2+x-1=6x-4

5. Bring all the terms to the left side of the equation.

color(violet)2x^2 color(brown)(-5)x color(turquoise)(+3)=0

6. Use the quadratic formula to solve for the values of x.

color(violet)(a=2)color(white)(XXXXXX)color(brown)(b=-5)color(white)(XXXXXX)color(turquoise)(c=3)

x=(-b+-sqrt(b^2-4ac))/(2a)

x=(-(color(brown)(-5))+-sqrt((color(brown)(-5))^2-4(color(violet)2)(color(turquoise)3)))/(2(color(violet)2))

x=(5+-sqrt(1))/4

x=6/4color(white)(X),color(white)(X)4/4

x=3/2color(white)(X),color(white)(X)1

However, looking back at the restrictions, ( color(red)(x!=1,1/2) ), x=1 is not a valid solution. Therefore:

color(green)(|bar(ul(color(white)(a/a)x=3/2color(white)(a/a)|)))