Answer :
[tex]-(1+7x)-6(-7-x)=36\\\\-1-7x+42+6x=36\\\\-7x+6x=36+1-42\\\\-x=-5\\\\x=5[/tex]
-(1+7x)-6(-7-x)=36 -- expand brackets
-1-7x+42+6x=36 -- combine like terms
41-x=36 -- add x to both sides and subtract 36 from both sides
5=x
x=5
-1-7x+42+6x=36 -- combine like terms
41-x=36 -- add x to both sides and subtract 36 from both sides
5=x
x=5
