How to solve this equation?

Question

https://gyazo.com/63d7e0ebf578afd27c4390f8a894c797

 

Above is a screenshot of the equation. Ignore the first line if you aren't familiar with finance. 

 

How do you go from the 3rd line of the solution to the 4th line?

Answer 1

3rd line reads:  

(167.50-38.86955)[1-(1+k)/1.092] = 6.44001(1+k)/1.092

 

128.63045[1 - (1+k)/1.092 ]    = 6.44001(1+k)/1.092

 

Distribute the 128.63045 on the left hand side:

 128.63045 - (128.63045)(1+k)/1.092 = 6.44001(1+k)/1.092

 

Then they treated "(1+k)/1.092" as a unit.  You have -128.63045 of them on the left and 6.44001 of them on the right.  When you add 128.63045 of them to both sides you get:

 128.63045 = 135.07046(1+k)/1.092

 

which they go on to solve for k.