Answer:
144
Step-by-step explanation:
First: 6x
Second: 6x+6
Third: 6x+12
Fourth: 6x+18
- Since they're multiples of 6
[tex]6x+6x+6+6x+12+6x+18=540[/tex]
[tex]24x+36=540\\[/tex]
Subract 36 from each side give us...
[tex]24x=504\\x=21[/tex]
[tex]21(6)+18=144[/tex]
Hope this helped! Please mark brainliest :)