Answer :
subtract 10 from both sides
-6.5x = 130 divide
-6.5 into 130
x = -20
[tex]3.5x=130+10x \ \ |\ subtract\ 10x\ to\ both\ sides \\\\3.5x-10x=130\\\\-6.5x=130\ \ | \ multiply\ both\ sides\ by\ (-10)\\\\65x=-1300\ \ | \ divide \ both \ sides\ by\ 65 \\\\x=-\frac{1300}{65}\\\\x=-20 [/tex]
