Rodney, Roger and Ron can lift a combined weight of 239 pounds.  Rodney can lift twice as much as Roger, and Roger can lift 7 pounds less than 4 times the amount that Ron can lift.  How much can Rodney lift?
Let x represent the amount that Ron can lift.
Roger: 4x-7
Rodney:2(4x-7)=8x-14
Total:x+4x-7+8x-14=239
13x-21=239
13x=260
x=<<20=20>>20
Rodney:8(20)-14=146 pounds
#### 146