Answer: [tex]x=\frac{5}{2}[/tex]
Step-by-step explanation:
Do you mean [tex]2[(12+2x)+(15+2x)]=74[/tex]? In that case just finish things inside the bracket first then multiply 2 inside.
[tex]2(12+2x+15+2x)=74[/tex]
[tex]2(27+4x)=74[/tex]
Then multiply 2 inside the bracket.
[tex]54+8x=74[/tex]
Move 54 to other side then we get,
[tex]8x=74-54[/tex]
[tex]8x=20[/tex]
[tex]x=\frac{20}{8}[/tex]
[tex]x=\frac{5}{2}[/tex]
(Note: If this is not what you mean then please let me know.)