Answer:
x = 7.8
Step-by-step explanation:
2.6 + x = 10.4
-2.6 -2.6
You do the inverse operations to find out x
[tex]2.6+x=10.4\\\\2.6-2.6+x=10.4-2.6\\\\\boxed{x=7.8}[/tex]
Hope this helps.