a(a-1)*(1-b) HELP

a(a-1)*(1-b)

 

\(a(a-1)*(1-b)\\ =a\;\;[({\color{red}a-1})(1-b)]\\ =a\;\;[{\color{red}a}(1-b){\color{red}-1}(1-b)]\\ =a\;\;[({\color{red}a}*1-{\color{red}a}*b)+({\color{red}-1}*1{\color{red}-1}*-b)]\\ =a\;\;[{\color{red}a}-{\color{red}a}b{\color{red}-1}+b]\\ ={\color{red}a}^2-{\color{red}a}^2b{\color{red}-a}+ab\\\)