Answer:
In an isosceles triangle, the legs of the triangle have same lengths.
[tex]{ \tt{perimeter = side + side + side}}[/tex]
• substitute:
[tex]{ \tt{23 = x + 2(2x - 6)}} \\ \\ { \tt{23 = x + 4x - 12}} \\ \\ { \tt{5x = 35}} \\ \\ { \boxed{ \tt{ \: \: x = 7 \: \: }}}[/tex]