Equations with Fractions, answers to 2 d.p. where necessary

Question

Need to find x =   or x =   , answer to 2 dp where necessary

 

1         .   +   1         .   =   2

2x + 4           2x - 4

Answer 1

1/(2x+4)+1/(2x-4)=2, multiply through by (2x+4)(2x-4)=4x²-16:

2x-4+2x+4=8x²-32,

4x=8x²-32, divide through by 4:

x=2x²-8,

2x²-x-8=0.

Quadratic formula: x=(1±√(1+64))/4=(1±√65)/4,

x=¼+√65/4 or x=¼-√65/4.

To 2 decimal places this is x=2.27 or x=-1.77.