I'm assuming that the capital and lower case x's are the same
[tex]x+7x-2=-20[/tex]
You need to get x by itself
Add 2 to each side
[tex]x+7x-2=-20[/tex] ⇒ [tex]x+7x=-18[/tex]
Add like variables together
[tex]8x=-18[/tex]
18÷8=[tex]2 \frac{2}{8} [/tex] ⇒ [tex]2 \frac{1}{4} [/tex]
Answer: [tex]2 \frac{1}{4} [/tex]