1. The problem statement, all variables and given/known data I'm refreshing my maths for the restart of uni and since I have problems finding 'x' equations, I'm stumped with this fairly easy question: 5-(x+2)=5x Now, because I had difficulty solving it I used an online calculator to solve and show me the steps so I can improve for next time. From looking through the steps - it introduces a '-1' to make it: 5+-1(x+2)=5x (website:http://www.algebrahelp.com/calculators/equation/calc.do?equation=5-(x+2)=5x&solvf=AUTO) This caught me out and I'm having trouble finding out where the -1 came from. I believe I have an inkling but would like to know the reason for the -1. Many thanks.